Ricky Walden captured four frames in succession to take a 5-3 lead over Mark Allen after the first session of their UK Championship semi-final in York.
Walden went 1-0 behind but levelled with a superb break of 124, only to be 3-1 down at the mid-session interval.
However, he seized on some Allen errors with breaks of 60, 66 and 98, before a clearance of 127 in the final frame.
The match concludes at 1900 GMT with Judd Trump awaiting the winner in Sunday's final.
Allen, who has beaten Adrian Gunnell, Ali Carter and Marco Fu so far this week but received rather more attention for his comments about snooker chief Barry Hearn, won a scrappy opening frame with a clearance of 24.
Walden immediately levelled in some style, however, even playing the pink left-handed during his century clearance.
Breaks of 85 and 54 seemed to put Allen in command at 3-1, and he had a golden opportunity to take a three-frame lead in the first frame after the resumption.
But he went in-off when potting the final green and Walden was soon level after adding the next.
Walden, 29, who beat Ronnie O'Sullivan to win the 2008 Shanghai Masters title as a qualifier, narrowly missed a century in frame seven, his break ending on 98 when a doubled final red bounced out of the jaws in the centre pocket, but his second century of the day earned him a two-frame cushion into the evening.