Neil Robertson overcame a dramatic fightback from Stuart Bingham to win 9-8 and book his place in the final of the williamhill.com UK Championship in York.
The Australian led 5-3 at the interval and won the first three frames of the evening session to move to the brink of victory.
But Bingham, who defeated Ronnie O'Sullivan in the last eight, had other ideas and battled back to level the match and send it to a deciding frame.
And it was Robertson who came out on top after an edgy safety exchange, finally getting his chance to leave Bingham leaving snookers.
Bingham led twice before the interval and potted more balls and scored more points in the session.
But he would have been relieved to close the gap in the last frame before the interval, having trailed 5-2 following a surge from the world number one from Melbourne.
Bingham made the early running and could easily have led 3-1 at the mid-session interval. A 72 break won him the opener and though Robertson responded with 70 in the next, Bingham restored his lead with an excellent 124.
The turning point came, though, when after a break of 51 in frame four Bingham broke down and Robertson eventually took the frame with a good clearance of the colours.
The Australian made the best of an unpromising position in the first frame back, potting a good long black and judging his cannons well to compile a high-quality 86.
He took the next as well after Bingham could not develop a couple of half-chances, the Basildon potter never in position and managing only 14 and 11.
Robertson looked to have wrapped up frame seven after a 68 break left Bingham needing four snookers, but a free ball and some superb safety brought the world number 10 back into it.
Having done the hard work, though, he rattled a green in the jaws and Robertson staggered over the line.
That left Bingham desperately needing to win the last and he did so with a 78 break, for a scoreline which was probably a fair reflection of the opening exchanges.
A relieved Robertson said afterwards: "I never threw it away, I wasn't really doing much wrong at all, Stuart was just playing fantastic snooker.
"I'm really proud of myself for the way I held myself together at the end.
"I tried not to celebrate because Stuart played an amazing game, some of the best snooker I've ever seen, so I know he must be absolutely devastated.
"I'd just like to congratulate Stu on a brilliant tournament, he's had a fantastic last month or so."
A deflated Bingham said: "I was just trying to make the score respectable and then all of a sudden I had a chance to win.
"I'm just gutted, lost for words."
Reigning champion Mark Selby meets Ricky Walden in the second semi-final on Saturday.