Barry Hawkins dug deep to claw his way back to 12-12 in his Betfair World Championship semi-final against Ricky Walden.
From 9-7 ahead at the start of play, Walden pulled 12-8 clear at the interval before Kent cueman Hawkins won the final four frames to set up an intriguing concluding session on Saturday night.
Hawkins, 34, started to show the kind of form which knocked out UK and Masters champion Mark Selby earlier in the tournament by producing breaks of 114 and 104 to reduce the deficit.
The 22nd frame proved to be the longest of the tournament as an out-of-sorts Walden struggled to find his form.
Left-hander Hawkins - playing in his 100th match of the season - landed a superb long pink under pressure before adding a simple black to win a gruelling 56-minute frame.
And after narrowing Walden's lead to a single frame, Hawkins swept to a break of 66 to end the session with the match in stalemate.
They are now set to resume at 7pm (BST), with the winner set to face defending champion Ronnie O'Sullivan.
The four-time world champion beat Judd Trump 17-11 on Saturday afternoon.