Mark Webster claimed a sensational 4-3 win over five-time world champion Raymond van Barneveld to reach the quarter-finals of the PDC World Championship at Alexandra Palace on Friday night.
The 30-year-old former world champion was trailing three times but managed to win the last six legs to secure victory and set up a last-eight clash with Michael van Gerwen or Gary Anderson.
Van Barneveld took the first set before Webster levelled at 1-1 as the Dutchman began looking frustrated and missed a couple of throws.
After a short break, Van Barneveld returned with a different shirt on and began to look more comfortable as he took the third set with a 101 finish.
Again his Welsh opponent struck back immediately, hitting back-to-back 180s and following with a clinical 101 finish to level the match once more.
But it started to look like his luck was out as Van Barneveld raced through the next set 3-0 to take the lead for the third time.
Webster, nicknamed Spider, then hit back from the brink of an exit as he won three legs to level the score at three sets all before successfully seeing out the deciding set.
A double 11 provided the crucial break he needed, and he moved further ahead after Van Barneveld missed 130 on the bull.
With the Dutchman sat on 40 after 12 darts, Webster held his nerve to take out 68 and record an excellent win.
Webster told Sky Sports 1: "I just felt the game was away from me - every set, every leg. I was just struggling, trying a bit too hard maybe.
"But I held myself together really well at the end. I'm over the moon. I can't believe I won...but I never envisaged I'd lose, if that makes sense. I'm contradicting myself, to a degree!"
The Welshman added: "The way the circuit works, my career was hanging by a thread coming into the tournament. So not only to win a game, but to get to the quarter-finals... I've done really well.
"My career's back on track. I'm still in the biggest tournament in the world, and who knows now?"
Earlier on Friday evening, Peter Wright played out an entertaining seven-set match against world youth champion Michael Smith to advance to the last eight.
Wright claimed a 4-3 victory to set up a match against Wes Newton, who earlier saw off Scot Robert Thornton 4-1, while Australian Simon Whitlock beat Kevin Painter 4-0.
Ian White produced a thrilling comeback to defeat Richie Burnett 4-3 after trailing 3-1 in sets, while Devon Petersen pulled off a shock 4-1 win over world number 11 Justin Pipe to complete the third round.