Alan Soutar survived eight match darts to come from 2-0 behind and knock world number 26 Mensur Suljovic out of the PDC World Championship.
The 43-year-old Scot moves into the third round at London’s Alexandra Palace after his 3-2 win.
Soutar sealed victory with a 144 finish to win the tie-breaker 6-4 against his Austrian opponent.
England’s Rob Cross won the late meeting of former world champions with a 3-1 win over Raymond van Barneveld.
Veteran Dutchman Van Barneveld, 54, started well and raced into a two leg lead with an excellent ‘Big Fish’ checkout.
The 2007 winner fired two treble 20s and the bullseye for a 170 finish, before going on to claim the first set.
Cross, who won his debut PDC world title in 2018, recovered from a 77 average in the opening set to win the next three and book his place in the third round.
Elsewhere, Danny Noppert beat Jason Heaver 3-1, before Gabriel Clemens cruised past Lewy Williams 3-0 and Chris Dobey came from two sets down to beat Rusty-Jake Rodriguez 3-2.
With 32 players remaining in the tournament, the third round begins on Monday.
‘I didn’t play my best either’
Arbroath firefighter Soutar first secured a two-year PDC Tour Card at the UK Qualifying School in February and believes he has lived a charmed life since.
Finding it difficult to describe his relief after the win, he said: “What happened there? In my head, I was dead and buried.”
“This year on the tour I’ve had a bit of the rub of the green and long may it continue,” he told PDC Darts.
Soutar also survived a tough first-round match on Sunday before edging out Brazil’s Diogo Portela 3-2.
“I didn’t play my best either,” he added after his win over Suljovic. “I think you have to learn on that stage to win without playing your best darts because I don’t think everyone does.”
He now faces Portugal’s Jose de Sousa in the third round.