Ronnie O’Sullivan is in danger of crashing out of the World Snooker Championship after Mark Williams established a 6-2 lead in their quarter-final clash on Monday.
Williams, bidding for a fourth world title, reeled off five consecutive frames at Sheffield’s Crucible Theatre to take control of the best-of-25 tie.
There was nothing to separate the veteran duo before the mid-session interval as they shared the opening four frames, which included a century from five-time world champion O’Sullivan.
But just 24 hours after criticising the lack of quality opposition outside the sport’s top stars, O’Sullivan endured a poor run that puts his World Championship challenge in jeopardy.
Williams edged a scrappy fifth frame before propelling himself into a healthy position with breaks of 72, 56 and a superb 130.
Earlier, Kyren Wilson moved into a 5-3 lead over defending champion Judd Trump in their quarter-final.
Wilson drew first blood with a break of 74 in the opener but world number one Trump responded with scores of 85 and 76 in the next two frames to edge ahead.
A run of three successive frames then helped Wilson build a 4-2 lead before Trump reduced the deficit by taking the seventh.
However, Wilson was able to restore his two-frame lead with a break of 79 just before the interval to leave Trump trailing after the first session for the third successive match.
Elsewhere in the last eight, Mark Selby has built a 5-3 lead against Australia’s Neil Robertson.
Selby edged a marathon 58-minute opening frame, the longest in this year’s tournament, and then reeled off the next four frames to race 5-0 in front.
However, Robertson hauled himself back into the match by winning the final three frames of the session, recording breaks of 83, 66 and 65.
In the battle of the qualifiers, Anthony McGill already looks on course for a maiden Crucible semi-final.
The Scot dominated the opening session of his meeting with Norwegian Kurt Maflin and will resume on Tuesday holding a commanding 7-1 lead.