Judd Trump's Scottish Open reached its conclusion after he lost a gripping deciding frame in a 5-4 quarter-final defeat to Thailand's Thepchaiya Un-Nooh.
Un-Nooh, ranked 54 places below Trump, won the opening frame but saw his opponent reply with breaks of 104 and 102 either side of a 79 for the Thai.
The pair shared the next two frames to make it 3-3, before Trump found himself one away from advancing when he made a break of 86, but Un-Nooh's 104 in the eighth forced a decider.
Un-Nooh missed an early opportunity to lock up his place in the final four, leaving the black over the pocket to allow Trump to force the re-spot, but he too failed to finish the job.
Instead, the black rolled back down the table for Un-Nooh, who this time made no mistake and punched his ticket to the semi-finals.
Un-Nooh will face Gary Wilson, who beat Kyren Wilson 5-3 in a match that led to the latter describing his namesake's attitude as "disgusting".
Gary, who knocked out world number one Ronnie O'Sullivan on his way to the quarter-finals, trailed 3-1 but then reeled off four frames on the bounce to set up his best-of-11 meeting with Un-Nooh.
While Gary Wilson was relieved to get the win, it later emerged that an incident during the mid-session interval had angered his opponent.
"I lost my head to be honest," the victor told Eurosport. "I actually went into the practice room and I had a lob at one of the balls to be honest. To be fair I just want to say a bit of a sorry to Kyren.
"He did say after the match that he thought my attitude was disgusting in the interval... I said 'oh, I didn't mean anything towards you about that'. That was just me getting annoyed. He said, 'yeah, well it can affect your opponent'.
"I go, 'well, sorry if it did but that's not my intention'. I was just letting off a bit of steam in the interval which I think I'm perfectly entitled to do."
World number two Mark Selby fell 5-2 to number four Neil Robertson, who will next face Joe O'Connor for a place in the final.
Robertson won four of the first five frames with breaks of 133, 99, 83 and 100.
Selby hit two century breaks of his own to narrow the gap to 4-2, before the 2017 champion wrapped things up in the seventh frame.
O'Connor, meanwhile, reached his second ranking event semi-final with a decisive 5-1 victory over fellow Englishman Ricky Walden.
Walden won the second frame to make it 1-1, but the Leicester man swept the next four, making a 127 break in the fifth frame and clinching victory with an 81.