Defending champion John Higgins went out of the Welsh Open in the fourth round, but Ronnie O'Sullivan is through to the quarter-finals in Cardiff.
Scotland's four-time world champion Higgins, 40, was beaten 4-1 by 24-year-old Welshman Michael White.
Englishman O'Sullivan, 40, had little trouble beating China's Yu Delu by the same score.
"I'm pleased to still be in the tournament. No matches here are a gimme," said O'Sullivan.
"John Higgins, the second greatest player I have ever seen, has been beaten. It takes a top player to have a slightly off day and you are going out."
O'Sullivan lost the opening frame when Yu fluked a re-spotted black.
"Yu Delu is a brilliant player so I was a bit nervous at the start," said O'Sullivan.
"I maybe was giving him a little bit too much respect. I lost the first frame but got some momentum going after."
O'Sullivan will play Mark Selby in the last eight after the world number one beat Welshman Mark Williams 4-2.
World number six Judd Trump missed a potential match-winning black in frame six, allowing Joe Perry to take the match into a decider, which he won.
Perry next faces Ben Woollaston, who won another all-English match, beating Martin Gould 4-1.
Northern Ireland's Mark Allen won a final-frame decider to beat Barry Hawkins of England 4-3 to set up a match against White.
Australia's Neil Robertson and Ding Junhui complete the quarter-final line-up. Robertson beat Hong Kong's Marco Fu 4-2 while Ding defeated Belgium's Luca Brecel by the same margin.