England's Luke Humphries caused the biggest shock of the Professional Darts Corporation (PDC) world championship as he sensationally knocked defending champion Rob Cross to reach the quarter-finals on Saturday (NZ time).
Humphries came from two sets behind to beat the second seed 4-2 on Day 13 in front of a sell-out Alexandra Palace crowd in London.
Cross looked comfortable early in the encounter as he raced out to a 2-0, but Humphries, 23, remained calm as he won the next three sets 3-1 to take the lead for the first time.
The Englishman then came back from 2-0 down in the sixth set, reeling off three successive legs to book his place in the quarter-finals.
Cross was gracious in defeat, saying this has been the hardest year of his short career.
"I'm disappointed," Cross said. "I didn't feel like I played. I felt a bit fatigued. Fair play to Luke, he played well.
"This is going to hurt, and I will bounce back next year. That's the monkey off my back now.
"This year has been tough and probably the hardest learning curve I have ever had in my life. I will go and enjoy a normal life now away from darts, and if I can do that, then I will be fine next year."
Humphries admitted he had to dig deep to defeat his fellow compatriot.
"When I went 2-0 down I said to myself 'if you want to be World Champion you've got to dig deep' and that's what I did, I didn't give up because you've got to fight back in those situations.
"Two years ago I might've given up there, but I believe in my own ability, and I'm hugely proud of myself for that performance tonight.
"I take a lot of inspiration from Rob and his win last year has given players like me the belief that I can win this, and if I keep showing resilience like this then I can go all the way."
Humphries will face world number 10 Michael Smith in the next round, who beat England's Ryan Searle 4-1 to reach the final eight.
Dave Chisnall set up a quarter-final against two-time champion Gary Anderson after a comfortable 4-0 win over Welshman Jamie Lewis.
Earlier, England's James Wade missed five darts to reach the quarter-finals before being knocked out 4-3 by compatriot Ryan Joyce.
Joyce fought back from 3-2 down to set up a last eight clash against world number one Michael van Gerwen.
Wade, who has been heavily criticised in the tournament for his behaviour in the tournament, refused to shake the referees' hands after the match.
Northern Irishman Brendan Dolan is through to the quarter-finals in London for the first time after a 4-1 victory over Dutchman Benito van de Pas.
Dolan will face England's Nathan Aspinall who progressed with a 4-3 win over South African Devon Petersen.
Four of the eight remaining players are unseeded.