Caroline Wozniacki v Lauren Davis (6-1, 4-6, 6-4)
9:31pm - And there it is, Wozniacki closes out the set and the match, an entertaining duel full of fast-paced tennis.
Check out a full wrap of the day's play here.
9:17pm - Clutch double break for Wozniacki and she inches closer to victory.
Davis replies with one of her own and we're back to even terms.
9:05pm - Wozniacki fires right back with a break of her own. She'll serve to try and make it 3-3.
9pm - Davis is on a roll, as she breaks early in the third set to take a 3-1 lead.
8:41pm - Davis breaks yet again to clinch the set. Huge turnaround from the American to send the match to a decisive third set.
8:34pm - Wozniacki breaks back to stay in the second set. She'll serve to try and make it 5-5.
8:30pm - Davis secures a huge break point to go up 5-3 in the second. She'll serve for the set.
8:08pm - They're locked at 2-2 in the second set.
7:51pm - First set done and dusted in smart fashion by Wozniacki.
7:35pm - Wozniacki blitzes her way to a 5-1 lead.
7:15pm - Wozniacki serves first and holds. Plenty of lengthy rallies already.
7pm - The final singles match of the day is about to get underway, as both players head out to centre court to warm up.
Julia Goerges v Jil Teichmann (6-3, 6-2)
6:16pm - Too much class from Goerges, as she books her quarter-final spot.
Caroline Wozniacki and Lauren Davis will now compete to decide who the German takes in theri round of 32 tie at 7pm.
6:05pm - Not much of a contest here, Goerges is waltzing away with this.
5:36pm - Goerges eases to a 6-3 win in the first set.
5:05pm - Service held both ways to begin the match.
4:52pm - The defending champion will look to take another step towards back-to-back ASB Classic titles against Swiss Jil Teichmann. Both players on court and warming up.
Serena Williams v Christina McHale (3-6, 6-2, 6-3)
4:40pm - Williams breaks yet again, and with it takes the match. Great effort from the underdog McHale, but Williams had too much class in the end.
She'll move on to face Laura Siegemund in the quarter-finals.
4:37pm - McHale isn't done yet. She hangs on to clinch a service break herself to survive another game.
4:32pm - Another break for Williams and she'll serve for the match next.
4:23pm - Williams earns what could be a match-deciding break in the final set. She'll now serve up 3-2.
4:13pm - Williams becoming pretty frustrated with the wind, which she's blamed for blowing a couple of her winners wide.
4:00pm - Williams looks a lot more like herself, as she closes out the second set to send us to a decisive third.
3:55pm - Williams serving for the set.
3:47pm - Double break for Williams and she's starting to find her rhythm.
3:43pm - Williams saves a break point and holds serve to go up 3-1 in the second.
3:28pm - Williams makes an early statement in the second set, breaking McHale's serve in the opening game.
3:23pm - There's the first set for McHale, 6-3. She's in a groove now and an upset is well and truly brewing.
3:12pm - Williams wins a break back and lets out a gutteral scream, trying to get herself fired up and into this contest. McHale to serve, up 4-3.
3:00pm - McHale breaks again! 4-1 up in the first set now. Could the world No. 88 shock Serena?
2:52pm - McHale earns the first service break of the match to go up 2-1.
2:48pm - McHale saves two break points in her first service game. 1-1.
2:40pm - The match is underway, Williams serving first under a full Auckland sun.
2:33pm - Williams and McHale take to centre court for warm-ups. Clearly the biggest pop of the day from the crowd during the Serena intro, there's no secret who the people are here to see today.
2:22pm - And the answer is no. Gauff sprays a forehand wide to give Siegemund victory 5-7 6-2 6-3.
That's a shame for the tournament - we all wanted to see Gauff up against Serena Williams in the quarter-finals - but a great result for the German, who played consistently throughout.
She will now meet the winner between Williams and American Christina McHale in the next stage. They're next on Centrecourt.
2:19pm - Siegemund holds to love again and is now just one game away from the match. Can Gauff hold serve to stave off defeat?
2:11pm - Siegemund holds serve to love and appears in command of this set at 4-2.
1:57pm - Gauff drops service, and Siegemund has her nose in front 2-1 in the third and deciding set.
1:50pm - Gauff begins the third set by holding serve, which is newsworthy in itself. She didn't win a service game during the second set and was broken twice when serving to open the previous two sets.
1:44pm - Gauff returns long and Siegemund holds serve to take the second set 6-2. We're into a third and deciding set now, with Gauff's service looking very shaky indeed.
1:40pm - And Siegemund breaks Gauff again - for the fourth time this set. The American hasn't actually held serve in the second set, which she now trails 5-2.
Siegemund now serving to lock the match up at a set each.
1:37pm - Predictably, Gauff breaks back for 4-2.
1:30pm - The German consolidates her second-set advantage with another service break to take a 4-1 lead over Gauff.
1:23pm - Another break puts Siegemund ahead 2-1 in the second set. That's the fourth time she's broken Gauff, while Gauff has also had four of her own.
1:19pm - This could be one of those matches where holding serve is more difficult than breaking, may be a reflection of windy conditions. Gauff immediately breaks Siegemund to put the second set back on service at 1-1.
1:14pm - The German wastes no time seizing an upperhand in the second set, breaking Gauff in the opening game, just as she did in the first.
1:07pm - Siegemund hits long and Gauff breaks to claim the first set 7-5. Great composure from the youngster to come back twice.
12:59pm - Siegemund serves for the set, but Gauff breaks back, as her rival sprays a return wide for 5-5.
This pair are very evenly matched, with Gauff ranked 67th and Siegemund at 73rd. They've never met before, but the German has a career-high ranking of 27, so obviously more experienced than the 15-year-old.
12:43pm - Siegemund continues to cause the American problems, breaking for a second time this set to reclaim momentum at 4-3.
12:29pm - Gauff breaks back to put the first set back on service at 2-2.
12:10pm - Play is underway on Centrecourt and Gauff has dropped her opening service game, handing the initiative immediately to Siegemund.
Kia ora, good morning and welcome to Newshub's live coverage of the ASB Classic women's tennis tournament from Auckland.
Day four will see secound-round singles matches completed, with top seed Serena Williams, defending champion Julia Goerges and former world No.1 Caroline Wozniacki again tacking the spotlight.
Kicking things off on Centrecourt, though, will be young American sensation Cori 'Coco' Gauff, regarded by many as the future of women's tennis.
Goerges and fellow German Laura Siegemund face double duty today, with both involved in singles and doubles action.
Siegemund faces Gauff in the opening singles match at noon, but will return later this afternoon for a doubles quarter-final with American Desirae Krawczyk.
Goerges faces Swiss Jil Teichmann at 3:30pm and will combine with French partner Caroline Garcia for doubles this evening.
The full ASB Classic schedule for Thursday is:
Not before 4:30pm
Doubles - Quarter-final
Desirae Krawyczyk (USA)/Laura Siegemund (Germany) v Kirsten Flipkens (Belgium)/Alison Van Uytvanck (Belgium)
Singles - Round of 16
Cori Gauff (USA) v Laura Siegemund (Germany)
Singles - Round of 16
1-Serena Williams (USA) v Christina McHale (USA)
Not before 3:30pm
Singles - Round of 16
Jil Teichmann (Switzerland) v 4-Julia Goerges (Germany)
Not before 7pm
Singles - Round of 16
5-Caroline Wozniacki (Denmark) v Lauren Davis (USA)
Doubles - Quarter-final
Caroline Garcia (France)/Julia Goerges (Germany) v Asia Muhammad (USA)/Taylor Townsend (USA)
Second seed Martic tumbles out of ASB Classic
The ASB Classic has its first big upset, after Alize Cornet ousted second seed Petra Martic in three sets in the round of 16 on Wednesday.
Cornet dropped the first set, but bounced back to prevail 3-6 6-4 6-4, and end her Croatian opponent's - and good friend's - tournament.
The 57th-ranked Cornet was more consistent with her first serve and broke Martic on six occasions to advance to a quarter-final.
Defeat was a blow for 28-year-old Martic before the Australian Open.
She has climbed to a career-high in the rankings, after reaching the quarter-finals at last year's French Open.
Cornet has won six career titles, but has always struggled at Grand Slams, failing to reach the last eight in 55 major appearances.
But she has a chance to go deep in Auckland, placed on the opposite side of the draw to tournament favourite Serena Williams and teenage sensation Coco Gauff.
Americans Williams and Gauff will play their second-round matches on Thursday.
Cornet will advance to face American Jessica Pegula, who proved far too strong for Tamara Zidansk in their round of 16 clash, coasting to a 6-2 6-3 victory.
In other action, Canadian fan favourite Eugenie Bouchard booked her spot in the quarter-finals with an impressive 6-4 6-4 win over Caroline Garcia.
American teenagers Catherine McNally and Couri Gauff coasted to a 6-3 6-2 win over Australians Jessica Moore and Arina Rodionova in their doubles match-up.
Local hope Erin Routliffe and American partner Allie Kiick took the opening set against defending singles champion Julia Goerges and Caroline Garcia, but soon found themselves on the wrong side of a 4-6 6-1 10-8 scoreline.
Rounding out day three, Amanda Anisimova continued her strong play with a 6-2 6-4 win over Daria Kasatkina.