Michael van Gerwen has recorded a 16-12 victory over Dave Chisnall to remain on course for his first World Matchplay title.
The world number one dropped the first three legs against his opponent, but a 145 checkout and 12-dart leg helped the Dutchman get back on level terms.
The next 14 legs were shared to see the score reach 10-10, but as Chisnall began to lose his range, Van Gerwen capitalised to win the final five legs to secure his place in the last four.
Van Gerwen will now play Simon Whitlock in the first of Saturday's semi-finals after the Australian thrower overturned an early deficit to run out a 16-10 winner over James Wade.
Whitlock conceded the opening four legs to the left-hander before winning nine of the next 10 to open up a 9-5 advantage.
Wade continued his attempts to get back into the contest, but the gap was never reduced to lower than three legs and Whitlock eventually saw out a comfortable victory.
