Mark Selby knocked Ronnie O'Sullivan out of the Scottish Open in a thrilling quarter-final in Glasgow that went to a deciding frame.
The Rocket, who has opted against competing at next month's Masters, fired in three century breaks compared to Selby's one in the opening five frames as he moved into a 3-2 lead.
Their first meeting since 2018 was making for compelling viewing and it looked as though O'Sullivan would pinch it when edging 4-3 ahead in a race to five.
A break of 56 from the Leicester cueman forced a decider - albeit after a controversial moment when the Rocket was penalised for missing a red which replays suggested he hit - while a run of 63 sealed victory.
"I always enjoy playing Ronnie. I see it as a challenge, he's probably the best to have played this game," Selby, whose top break was 120 in the opening frame, said afterwards on Eurosport.
"You always know you'll be up against it and you have to play as good as you can possibly play. I thought I've got nothing to lose.
"I wasn't feeling great before the match. I went in as the underdog. Everyone was expecting him to win and I just went out there and enjoyed it."
The pair had exchanged a humorous 'rock, paper, scissors' greeting before the match, following on from O'Sullivan's 'fist bump' with James Cahill and the referee ahead of their second-round contest to avoid germs.
Afterwards, O'Sullivan paid tribute to Selby's resilience.
"Mark played well, he played good stuff, good safety and a brilliant break at the end under pressure. That's what champions are made of," O'Sullivan said.
"I'm happy with my performance this week. Mark's a brilliant match player. I think I've done alright, I'm happy to be able to compete."
Selby will play David Gilbert in the semis after he surprisingly got the better of world number one Judd Trump by virtue of a 5-2 win, the defining moment for the winner a 142 clearance in the sixth frame.
Earlier on Friday, defending champion Mark Allen beat Scotland's Scott Donaldson 5-1 in the first quarter-final and will next meet Jack Lisowski.
"The schedule this week has been disgraceful when it comes to my matches," the Northern Irishman said.
"Being defending champ, I knew I'd start off on Monday. Then I was 10am Wednesday, 10am Thursday, then last on at night and then first on Friday.
"Some very strange decisions, but no one wants to take the blame for it."
Lisowski defeated Thailand's Thepchaiya Un-Nooh 5-3 to book that semi-final spot against Allen.
The world number 14 had made the tournament's highest break of 143 in the third frame.