Ronnie O’Sullivan beat Judd Trump 9-8 on the final black in a thrilling Tour Championship semi-final in Llandudno.
Trump, 29, led 6-2 at the mid-session interval and moved 8-5 up when he took a frame lasting more than 40 minutes.
But O’Sullivan – seeking the world number one spot with a tournament win – found a 130 clearance followed by 134.
‘The Rocket’ claimed five of the last six frames and pounced when Trump missed yellow for match ball in the decider to win through to the final.
The world number two punched the air after rolling home a testing black for victory and he will now play either Neil Robertson or Mark Allen, who meet in their semi-final on Friday.
That encounter will struggle to match the drama O’Sullivan mustered in a fightback which saw him fall more than 50 points behind in the decider when he was penalised for his waistcoat making contact with a ball.
He fluked a pink, which briefly looked like it would be decisive, before Trump was ultimately presented with a yellow across the baulk cushion as match ball, only to rattle it against the jaws at pace.
O’Sullivan showed moments of his fluent best, taking the first frame of the evening session with a break of 82 in around seven minutes, while his 130 clearance took a similar time.
Trump will rue missed chances and occasional poor fortune, notably when he cut home a key blue which would have given him an 8-4 lead, only to see the white disappear into a pocket, allowing O’Sullivan to move within just two frames rather than be four down.
The five-time world champion took full advantage and will usurp Mark Selby at the top of the rankings if he takes the title.