Neil Robertson failed to build on his superb defeat of Ronnie O'Sullivan as Barry Hawkins claimed a place in the semifinals of the Ladbrokes World Grand Prix.
Robertson eased past five-time world champion O'Sullivan 4-1 in their second-round meeting on Thursday afternoon but was unable to replicate that form later as he lost 4-2 to Hawkins in the last eight.
Hawkins, who beat Judd Trump 4-1 earlier in the day in Preston, did not trail against the Australian after taking the first frame with a break of 81 following a Robertson mistake.
Robertson levelled but Hawkins took the next two in scrappy circumstances. Hawkins missed a chance to settle the match in the fifth frame, and Robertson replied with a frame-winning run of 51, but he made no mistake in the sixth, securing victory with an 85 break.
Hawkins told ITV Sport: "I wouldn't say it was a solid performance, we both missed a few, but I'm pleased to get past Neil and be in the semifinal.
"I finished off well, I needed to win that frame, as I've started to get a name for myself for collapsing after getting in front."
Robertson's performance contrasted with his effort in the afternoon, when he built a 3-0 lead against O'Sullivan and threatened a whitewash. O'Sullivan eventually came from behind to win a tight fourth frame but Robertson went through after a break of 83 in the fifth.
"It was probably one of the better results I have had against him," Robertson said. "There probably wasn't a lot he could have done.
"My safety was fantastic and long potting was good. I scored very heavily from good positions too. It was very pleasing all round."
Liang Wenbo claimed his place in the last four with a hard-fought 4-3 victory over Joe Perry.
Wenbo rattled in two centuries but was never able to pull clear as the pair traded frames throughout.
His 109 in the third frame was followed by 72 from Perry in the next. He hit 129 in the fifth only for Perry to reply with 122, but he edged a tight decider, punching the air as he secured victory.