Phil Nixon will meet fellow outsider Niels de Ruiter in the semi-finals of the Lakeside World Championship after both claimed narrow 5-4 wins.
De Ruiter staged a superb recovery to secure the win
Qualifier Nixon, from Durham, held his nerve after 15th seed Paul Hanvidge had fought back from 4-1 down to level at 4-4 to win.
De Ruiter, the 11th seed, recovered from 2-0 and 4-2 down to defeat England's Gary Robson.
It kept alive Dutch hopes of winning a second world title in two weeks.
Nixon came through three separate qualifying competitions at county, national and international level to secure his Lakeside debut and he looked to be cruising into the semi-finals when he led 4-1.
But he squandered six darts to win the match 5-1 and Hanvidge worked his way back into it. Nixon regained his composure in the deciding set, though, completing the win with a 105 checkout.
It has been a surprising tournament
"I'm elated," he admitted. "I just had to keep telling myself not to muck it up - just hit the double and enjoy it.
"I want to keep winning now. I'll go to bed early tonight, have a good rest, get up early in the morning and think positive."
De Ruiter looked to be heading for defeat when, after levelling the match at 2-2, he lost the deciding leg of the fifth set despite hitting two 180s.
Robson took that leg with a superb 121 checkout and also won the next set to put himself on the brink of victory.
But back came the the Dutchman and, after reducing his arrears to 4-3, he restored parity again after a 160 finish to take the contest all the way.
Both players struggled to hold their throw, Robson hitting 93 on the bullseye to save the match, before De Ruiter finally made the breakthrough with double 18 with his sixth match dart.
"I was proud of myself that I kept fighting. When I was 2-0 down I still believed in myself," he said.
"It would be fair to say it's surprising that I am the only Dutchman left in the competition but it has been a surprising tournament."