Daryl Gurney booked a semi-final place at the World Matchplay with a 16-13 success over Mensur Suljovic.
Gurney trailed 4-2, 5-3, 6-4 and 11-9 but kept in touch with his opponent, before finding his best darts as the pressure increased.
From 11-9, the 31-year-old won four of the next five legs to move in front and while Suljovic levelled again at 13-13, Gurney stepped up a gear to quickly wrap up a 16-13 success.
"I can't put it into words, really," said Gurney.
"I just kept on chasing him. From the start of this year I've learned to be patient.
"I eventually got in front and that's all I needed."
An emotional Gurney hit 13 maximums and 50 per cent of doubles and was delighted with his performance.
"I missed a few at the start - a crucial 71 in the first session... and that hurt me.
"I knew I could come back at him."
A semi-finalist at the UK Open earlier in the season, this win represented another step forward in the career of the Northern Irishman, tipped at 80/1 prior to the tournament by our darts ace Chris Hammer.
And Hammer's followers know already that it will be a profitable event come what may, as Gurney was also put up at 10/1 to win his quarter.
Next for Gurney is a meeting with Peter Wright, who also turned on the afterburners to see off Darren Webster 16-12.
Wright was far from his best and trailed 11-9 heading into the second interval, but that break did him the world of good and the match changed course soon after.
Webster missed double one for what would've been a 12-9 lead and from there, Wright won six legs in a row before his opponent earned a stay of execution by holding throw bravely.
With the darts, however, Wright was able to control the 28th leg and earn his second semi-final place, two years on from his first.
Wright's form over the closing eight legs saw his average climb just above 100, but he'll look for more than his five maximums when taking on Gurney next.
"Playing against Darren, it's hard," Wright said, before acknowledging that his semi-final opponent will represent another stern test of his title credentials.
"Daryl's playing fantastic, he's on a high, he owns that stage at the moment.
"It's great when you feel like that."
Thursday's World Matchplay results
Quarter-finals (best of 31 legs)
Daryl Gurney 16-13 Mensur Suljovic
Darren Webster 12-16 Peter Wright
*Each game must be won by two clear legs, with up to a maximum of five additional legs being played before the sixth additional leg is sudden-death
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