Martin Adams was knocked out of the 2014 BDO World Darts Championship in the quarter-finals on Friday night.
The three-time champion was beaten by Jan Dekker, who recorded a three-dart average of 91.42.
Dekker raced into a 3-0 lead before Adams closed the gap to 3-2. The Dutchman then booked his place in the last four at Lakeside for the second time in four years by winning the next two sets, both of which went to deciding legs.
Dekker will face Alan Norris in the semis on Saturday, after the 41-year-old averaged 97.47 in overcoming second seed James Wilson 5-2.
The weekend's first men's semi-final will see top seed Stephen Bunting take on fellow Merseysider Robbie Green.
In the women's competition, defending champion Anastasia Dobromyslova will meet Lisa Ashton in the last four following a 2-1 victory over Fallon Sherrock.
Ashton booked her place in the last four by defeating Tamara Schuur in straight sets.
In the other half of the women's draw, world number one Deta Hedman will clash with Demmark's Ann-Louise Peters for a place in the final.
Robert Summerscales
