World champion Mark Williams recovered from 3-0 down to defeat Jack Lisowksi 5-3 and reach the semi-finals of the Hong Rui Ma Yushan World Open in China.
Lisowksi dominated the early exchanges, with a century break in the third frame the highlight, but Williams pulled one back before the interval with a break of 96 and then benefited from a fluke on the last red to close the gap to one frame.
Englishman Lisowski missed a pink for a 4-2 lead, playing with his unfavoured right hand instead of the rest, and Williams made him pay.
Welshman Williams said on worldsnooker.com: "I just hung in there at 3-0 down because Jack was immaculate.
"He had an easy clearance to go 4-2 up then he played the pink right-handed.
"He might be really good right-handed but if he had got the rest out it was unmissable and then he probably would have won.
In the last four Williams will face Noppon Saengkham of Thailand, who defeated China's Xiao Guodong 5-1, while the other last-four clash will pit David Gilbert against Barry Hawkins.
Gilbert is through to only his second semi-final at a ranking event after beating Marco Fu 5-3, notching a break of 122 to go 4-1 ahead and then withstanding a Fu fightback.
Hawkins was the runner-up to Mark Selby at the China Open in April and is again showing strong form, moving through to the last four with a 5-3 victory over Gary Wilson.