11:10am - That is all from me today. Head to Newshub.co.nz for all the reaction from the fight. Thanks for tuning in.
11:00am - For a fight recap, click here.
10:54am - Here is some Twitter reaction.
10:51am - "Today I got beaten by a better fighter," said Joseph Parker. "No regrets, I'll take it on the chin. We'll be back again".
10:48am - Anthony Joshua had plenty to say after the fight.
"My strategy was to stick behind the jab and that secured me another world title belt," he told Sky Sports UK.
"I thought it was hard, but going the twelve rounds was light work.
"I know the bookies say I might get a knockout but forget the hype, Parker was a world champion.
"This was a boxing match, not a fight. Parker said this would be war, I said this would be boxing finesse."
10:46am - Joshua is 21-0 in his career, while Parker falls to 24-1.
10:42am - The Brit now has four belts and Deontay Wilder awaits for the Brit. That is Parker's first loss.
10:40am - Time for the scorecards. Anthony Joshua takes it via a unanimous decision with scores of 118-110 twice and 119-109, adding the WBO strap to his collection. The crowd loves it
ROUND TWELVE: Here we go, the final round, the championship round. Can Parker get the breakthrough here? The crowd erupts, as Joshua gets the Kiwi on the ropes. Parker goes looking for the big blow; he can't get the breakthrough. 100 seconds remain - Joshua lands a big uppercut, and now there are 80 seconds left, Joshua lands big again, but the Kiwi stands tall. 60 seconds left, and both trade blows. Just like that, it is all over. Both hug and that is it. It will go to the scorecards.
ROUND ELEVEN: Joshua has found his second wind in the later rounds and is back on top. Parker is trying to find that big punch but is having no luck. Parker rocks Joshua but the Brit is fine. Another close round which would have to be a 10-10.
ROUND TEN: Eddie Hearn just spoke to Sky Sports UK, and he said Parker has only won two rounds. Joshua has only ever gone past the tenth round once. Both fighters are dancing around the middle of the ring, and Parker lands a nice body punch. Parker's face is all red right now, and once again, the Brit's tape comes loose. That round goes to Joshua. It looks like Parker has to win by KO if he wants to avoid that 0.
ROUND NINE: Four rounds remain. Parker lands some jabs, but they don't hurt the man from Watford. Giuseppe Quartarone splits the fighters up once again, and I'm sure many agree, he is ruining the flow and the titanic tussle in this fight. Parker lands some great punches, but the ref jumps in. 'AJ's' tape comes loose on his gloves, and the fight stops for 30 seconds while the tape gets cut. The round comes to a close, and that would have to be a draw, 10-10.
ROUND EIGHT: Both fighters come out swinging to start round eight. They both land some good shots, but once again, Quartarone is breaking the opponents up when they get close to one another. The round draws to a close, and Joshua lands some powerful jabs. Joshua's tape ones lose on his gloves. That round goes to 'AJ'.
ROUND SEVEN: The second half of the fight is here. Both fighters come out of the blocks slow here, but Parker throws some good punches, but they just miss. 'AJ' lands a couple of sharp jabs, and as Giuseppe Quartarone breaks them up, the Brit throws an uppercut while he is in the middle and the ref wasn't happy with that. Parker lands some good body shots. It really looks like the man from the UK is looking tired. That was a close round, could be a 10-10 but could also go either way.
ROUND SIX: Joshua is closing the distance and Parker comes out swinging to start the round, and the Kiwi connects. 'AJ' got hurt right there and both are picking up the pace. Joshua lands a solid punch, but Paker hits back twice as hard. He connects again, as the Brit is starting to slow up. Parker is growing in confidence right now as the Kiwi lands more punches to the body of Joshua. He has found a new gear as the round ends. Definitely a Parker round, 10-9.
ROUND FIVE: Joshua lands with a left hook, and that hurt Parker. Still, the range continues to be a problem, but the Aucklander lands a combo attack, and that was good by Parker. The Kiwi lands another solid punch. This is looking like a good round for Parker. That round goes to Joe, 10-9, as he walks back to his corner with a big smile on his face.
ROUND FOUR: It looks like both are trying to conserve their energy right now. 'AJ' lands with a jab and it may have hurt Parker. The Brit is punching fast here with some good combos. Parker is going fast, but his punches are not landing. The Kiwi is picking up the face as the round heads into the final 30 seconds. Joshua lands a nice left hook as Parker continues to struggle with the range. The round goes to Joshua, 10-9.
ROUND THREE: Parker swings, and it wasn't even close. The Brit is once again doing a great job keeping distance and keeping Parker on the ropes. They are back in the middle of the ring. Joshua connects, and Parker then wraps him up. Parker connects a nice left hook before both hit heads, and the referee puts his arm between the two. Another Joshua round, 10-9.
ROUND TWO: Parker starts the round on the back foot and is backing towards the ropes. The Kiwi lands a couple of jabs as both fighters move back to the middle of the ring. 'AJ' is keeping his distance and his reach advantage is showing. Joshua looks like he is having trouble with his shorts as the round draws to a close. The round is over, and that one goes to the Brit, 10-9.
ROUND ONE: Here we go!!! Round one is underway in Cardiff. Both fighters are finding their range early. Both landed some early jabs, but not causing damage. The 'Anthony Joshua' chants are starting around the ring. Parker is near the ropes, and it looks like the Brit is trying to trap the Kiwi. The round ends with a body shot by Joshua.
The first round goes to Parker, 10-9, but only just.
9:52am - Make sure you refresh the page for the lastest each round.
9:51am - Both boxers touch gloves, and it is finally here!! Round one is moments away.
9:48am - LETS GETS READY TO RUMBLEEEEEEEEEEEEEEE!!!!
9:45am - Main event time between undefeated champions.
9:44am - The crowd is still booing as the New Zealand anthem comes to a close.
Now it is time for God Save the Queen.
9:42am - Joe looks cool and calm. He is doing some shaddow boxing while the anthems are being sung - oh and the crowd is booing.
9:40am - Now it is time for the National Anthem. Joe will have the Samoan and New Zealand ones performed.
9:38am - Finally, Joshua is walking to the ring in his hotel bath robe... Well that is what it looks like to me.
9:36am - A very long intro here for the Brit. He hasn;'t walked out to the ring yet.
9:34am - Now it is time for 'AJ' to walk to the ring. The crowd is going to explode if they haven't yet.
9:33am - Parker is in the ring and the boos are loud and they quickly turn to cheers when Joshua shows up on the big screen.
9:32am - Parker is wearing white as 'Can't be Touched' blasts around! The crowd is booing the Kiwi. It is a long and slow walk to the ring.
9:30am - The Anthony Joshua chants have started as Parker gets ready to walk out to the ring. The Haka is in the background too.
9:28am - Here we go! The crowd is stilling signing, but Michael Buffer is about to call Joseph Parker out to the ring.
9:24am - We have been informed that referees and officials have checked Parker's hand wraps ahead of the fight. The BRits camp had questions about them. Was that a tactic to unsettle him? Might be.
9:22am - Eye of the Tiger, Sweet Caroline. Seven Nation Army, all songs I hear when the darts on are on. This arena is loud!
This is intense, and it is hard to find words to describe the feeling right now.
9:19am - A few excited faces in the Newshub office, some nervous ones too. Won't be long now before the fighters are making their way to the ring.
9:17am - One last time to vote on who you think will win. Vote on the poll below.
9:12am - Newshub's Tova O'Brien has said that there have been multiple arrests in the crowd before the fight has even begun.
9:11am - I might be wrong, but it sounds like the crowd is chanting 'Micahel van Gerwen'.
9:11am - All the undercards are complete. The next men out on the ring will be Joseph Parker and Anthony Joshua.
9:03am - They have just shown a replay of the knockout blow, and wow that was a brutal shot.
9:03am - Alexander Povetkin beats David Price! The Russian hits the man from Liverpool, and he stumbles over, and the fight is over. Doctors are currently assessing Price in the ring who doesn't look good. But he is on his feet.
9:00am - This will be great to hear when Parker walks out.
8:55am: Price gets the Russian at the end of the round and he falls back onto the ropes but the bell saves him for now. What a massive shot by Price.
8:54am - David Prince falls to the canvas after a great shot by Povetkin, and he is not happy. He hits the ground, and he gets up and continues.
The man from Liverpool has a big cut over the left eye.
8:50am - Incase you missed it, Kiwi Mose Auimatagi Jr beats Morgan Jones in the first fight of the night in Cardiff.
8:44am - Price vs Povetkin is underway in Cardiff. This should be a cracking fight.
8:32am - Ross Karl believes it is time Joseph Parker to set aside 'nice guy' image
8:30am - One more undercard remains. David Price, the man who knocked Anthony Joshua to the ground a few years ago, faces Alexander Povetkin, the former WBA heavyweight champion.
Povetkin currently holds the WBO International heavyweight title, and the WBA Inter-Continental heavyweight title.
8:28am - A convincing win for Ryan Burnett against Yonfrez Parejo who defends his WBA (Super) bantamweight title. He is now 19-0.
8:22am - Joseph Parker has spoken from the changing rooms. He is getting his hands strapped right now.
"I feel great, we are relaxed and just chilling out," he told Sky Sports UK.
I'm very confident in what I can do in the ring.
"I'm ready to put in a great performance.
"I feel it is my time to make my mark on the world and the heavyweight division.
8:19am - If Joseph Parker beats Anthony Joshua, the 'King of Pies' has something else on the menu for his post-fight festivities. Click here to find out exactly what he will feast on.
8:15am - Speaking to Sky Sports UK, Sugar Ray Leonard said he has just spoken with Anthony Joshua.
"I like what Anthony Joshua represents, he is a great champion and very good for the sport," he said.
"He is calm and collected. He is a champion and that's what it is all about."
8:03am - We are in the seventh round between Ryan Burnett and Yonfrez Parejo. Nothing spectacular just yet, this might go the distance at this rate.
7:59am - Right now Joseph Parker is paying $4.20 to win at the TAB while Anthony Joshua is paying $1.20.
7:54am - Joseph Parker is getting some love from well known New Zealanders and Australians.
7:36am - Former All Blacks captain Richie McCaw is backing Joseph Parker. Click here to find out what he had to say about the WBO Champion.
7:35am - Next up is Ryan Burnett, defending his WBA bantamweight title against Yonfrez Parejo.
7:30am - Here are the results from the undercards so far.
Anthony Crolla def Edson Ramirez via decision
Josh Kelly def Carlos Molina via decision
Joe Cordina def Hakim Ben Ali via TKO3
Joshua Buatsi def Bartlomiej Grafka via decision
Mose Auimatagi Jnr def Morgan Jones via TKO6
7:22am - Anthony Crolla beats Edson Ramirez by unanimous decision with scores of 100-91, 100-90 and 98-92.
Two undercards left before the main event.
7:15am - Sugar Ray Leonard and Frank Bruno are in the stadium watching the fight.
7:12am - Anthony Joshua has just arrived at the stadium with a police escort, and I can say, the Principality Stadium just erupted. They are excited, and so am I.
7:09am - If you want to go out and watch the fight, here is a list of places which are broadcasting the fight.
7:04am - Newshub's Tova O'Brien just caught up with Temuera Morrison outside the Principality Stadium.
6:44am - Joseph Parker has arrived at Principality Stadium.
6:35am - Up next: Anthony Crolla faces Edson Ramirez for a world lightweight title.
6:30am - Newshub's biggest boxing fans made their predictions on who will win the fight. Click here to see who they think will reign supreme.
6:22am -Josh Kelly beats Carlos Molina by unanimous decision with two scores of 98-92 and 99-91.
His prize is the vacant WBA International welterweight title.
6:05am - Dillian Whyte has just made his prediction on Sky Sports UK, and he believes Anthony Joshua will be victorious.
"I'm expecting Parker to start tactical, he's come in very light," he said.
"Joshua can go for the kill, mid-late rounds.
"I think Joshua is going to win between rounds one to seven."
Do you agree with him? Vote in our poll below on who you think will win.
5:52am - Joseph Parker's sparring partner Malik Scott believes the kiwi's punching power is at its highest level ever. Click here to read the full story.
5:37am - The next fight on the undercards is Josh Kelly vs Carlos Molina.
Kiwi UFC fighter Mark Hunt is in Cardiff for the fight backing Joseph Parker.
5:34am - Here are the results so far of the three undercard:
Joe Cordina (UK) beat Hakim Ben Ali (BEL) by TKO.
Joshua Buatsi (UK) beat Bartlomiej Grafka (POL) by decision.
5:24am - Joe Cordina beats Hakim Ben Ali by TKO for his seventh professional victory. His home fans are happy.
5:13am - Joshua Buatsi has also prevailed in Cardiff with a win over Bartlomiej Grafka. Right now, Joe Cordina is facing off against Hakim Ben Ali.
5:10am - It has been a great start to the night for the Kiwis with Mose Auimatagi Jr winning his undercard against Morgan Jones.
Mose Auimatagi Jr has done his part to ensure a big night for New Zealand with a spectacular final-round stoppage of unbeaten Welshman Morgan Jones in Cardiff.
The bout kicked off the undercard for the blockbuster heavyweight unification fight between Anthony Joshua and Kiwi Joseph Parker at the Principality Stadium.
The 22-year-old Aucklander started well but was staring down the barrel of a points loss even before he was floored by a Jones right hook early in the sixth and final round.
He recovered superbly to unleash a combination of body shots which sent Jones running, the referee stopping the fight with just eight seconds to go and victory looming for the hometown hope.
5:05am - Good morning and thanks for tuning in to Newshub's live updates of the upcoming bout between Joseph Parker and Anthony Joshua.
Hello and welcome to live updates of tonight's massive showdown between Joseph Parker and Anthony Joshua from the Principality Stadium in Cardiff.
Plenty is on the line for both fighters with four heavyweight belts up for grabs. We will be keeping you up to date with all the undercard fights and then round by round updates of the main event.
There are eight undercards scheduled before the big fight. Parker vs Joshua will not be before 9:30 am (NZ time).
Anthony Joshua (UK) v Joseph Parker (NZ) (9:30 am earliest)
David Price (UK) lost to Alexander Povetkin (RUS) by TKO
Ryan Burnett (UK) def Yonfrez Parejo(VEN) by decision
Anthony Crolla (UK) def Edson Ramirez (MEX) by decision
Josh Kelly (UK) def Carlos Molina (MEX) by decision
Joe Cordina (UK) def Hakim Ben Ali (BEL) by TKO
Joshua Buatsi (UK) def Bartlomiej Grafka (POL) by decision
Morgan Jones (UK) lost to Mose Auimatagi Jnr (NZ) by TKO
TAB ODDS: Head to head - Joseph Parker $4.75 Anthony Joshua $1.16
Method of victory: Parker KO - $6.00 Parker decision - $13.00 Joshua KO - $1.37 Joshua decision - $5.50
Tale of the tape:
JOSEPH PARKER: DOB: January 9, 1992, Residence: Las Vegas, USA, Age: 26, Height: 193cm, Reach: 193cm
Professional debut: July 5, 2012, Wins: 24, Losses: 0, Draws: 0, Bouts: 24, Rounds: 123, KOs: 18
ANTHONY JOSHUA: DOB: October 15, 1989, Residence: Watford, UK, Age: 28, Height: 198cm, Reach: 208cm
Professional debut: October 5, 2013, Wins: 20, Losses: 0, Draws: 0, Bouts: 20, KOs: 20
Pre-fight banter: Ross Karl: Time for Joseph Parker to set aside 'nice guy' image
The one thing everyone will tell you about Joseph Parker is he’s 'nice'.
When you see him, you get a big smile and a warm handshake/hug. He makes you feel like the only person in the room.
He’s almost impossible not to like.
And it’s good for people to be nice, but it doesn’t win you big fights against a monster like Anthony Joshua.
Some controlled anger in the ring would do Parker the world of good.
That’s why I like the way Anthony Joshua has been mouthing off in the build-up to Sunday's world title unification bout.
He’s called him weird, he’s called Parker’s team backstabbers, and he's refused to shake Parker's hand. On Wednesday, he reiterated Graham Norton’s statement that he’s the 'King of the Pies'.
The more reasons Joe has to dislike this guy, the more sting there should be in his knockout punch. That could be vital, considering Joshua has shown he can get up off the canvas and then knock out a great opponent.
Parker hasn’t thrown any punches in anger so far in his career. He didn’t need to against the early bunnies, or the likes of Takam or Ruiz. There’s never been anything said in press conferences to anger him.
Every press conference I’ve been to has been respectful.
That’s good, that’s Joe, but I’m sure this time, behind the scenes, he won’t be happy.
This is the first time he’s ever really been in the firing line from an opponent.
That's good. If you don’t like someone, you want to knock them out for yourself, as well as for the win.
It'll help him go in for the kill.
If Wladimir Klitschko had that killer instinct, Joshua wouldn’t even have the belts now. He had his chance to win, but didn’t have the 'Eye of the Tiger', so to speak.
In a blood sport, it helps to smell blood.