Seven-time world champion Ronnie O’Sullivan suffered a 4-0 defeat by Shaun Murphy at the Champion of Champions tournament in Leicester.
Murphy, the 2005 world champion, lost this year’s World Championship final in a deciding frame to Wu Yize.
There was a chance the pair could meet in the quarter-finals at the Champion of Champions, but Wu was knocked out 4-3 by Chinese compatriot Chang Bingyu.
O’Sullivan, who has been struggling for form, was playing for the first time since losing to Ka Wai Cheung at the Northern Ireland Open last month.
The 50-year-old found himself 2-0 down against Murphy, who knocked in a 68 in the second frame.
Murphy made a 41 break to take the next frame before triumphing in a tense fourth frame 61-42 to secure victory and a spot in the last eight.
Chang opened with a 109 break against Wu and, after losing the following three frames, reeled off three in a row himself to progress.
However, Chang was then thrashed 6-0 by Murphy when they met later on, with the Englishman producing breaks of 50, 142, 107, 78 and 70 to reach the last four without having dropped a frame.
Neil Robertson and Chris Wakelin have already booked their spots in the semi-finals, while the fourth player is still to be decided.