Top seed Stephen Bunting battled back from losing the first two sets to beat Rick Hofstra 5-2 and reach the BDO World Darts Championships semi-finals.
The 28-year-old from St Helens survived a scare to win through to his first last-four appearance at the Lakeside, where he will face Robbie Green.
Green, 39, beat countryman Tony Eccles 5-2 in the first quarter-final.
Martin Adams reached the last eight, where he will face Jan Dekker, with a 4-1 victory over Ross Montgomery.
Dutchman Dekker beat Belgian Geert de Vos 4-2.
Bunting squandered a host of set-darts as Hofstra took a commanding lead in their quarter-final clash, but "The Bullet" fought back to beat the Dutchman and set up a semi-final against Green.
Adams, who has returned to form after a difficult 2013, took a 2-0 lead but Scot Montgomery hit back in the next before the 57-year-old Englishman closed out the victory at Frimley Green.
If Adams, a three-time champion, beats Dekker, he will face either James Wilson or Alan Norris, who meet in Friday's other quarter-final.
In the women's tournament, Denmark's Ann Louise Peters beat Julie Gore of Wales 2-0 to reach the semi-finals, where she will face England's Deta Hedman, who beat German Irina Armstrong 2-0.
England's Lisa Ashton beat Aileen de Graaf of the Netherlands 2-1 to book her place in the quarter-finals.