Crucible showman Ronnie O'Sullivan turned on the style as he went close to thrashing Mark Williams with a session to spare.

Williams took the final two frames of the session to guarantee they must return on Monday evening, but the Welshman is surely destined to lose to O'Sullivan at the Crucible for the fourth time in seven years.

The pair have met in 2006, 2008 and 2010, with the result going O'Sullivan's way each time, and this time he has armed himself with an imposing 11-5 lead in their best-of-25-frames match.

In the first frame of the afternoon, Williams missed an attempted plant to let O'Sullivan in for a break of 107. The gap went to three frames, and it was soon four. Williams was put in deep trouble behind the brown, and played the white off the side and top cushions but the wrong side of his intended target red, missing all the balls and leaving an easy starter.

O'Sullivan had a plant red in a break of 74, and Williams could only stew in his seat. A 51 guided O'Sullivan towards an 8-3 lead, before a 68 took him to the interval four frames from victory.

The genius was still at work when they returned, firstly with a 128 which was followed by a sprint to 93. That made it nine frames in a row for the 36-year-old from 3-2 behind, and a free Monday evening was by that stage looking a probability.

O'Sullivan had chances early in the 15th frame too, but two reds were not followed by colours and Williams seized his chance, making 86 to guarantee him another night in Sheffield. The 37-year-old Ebbw Vale man scrambled through what proved easily the scrappiest frame of the session to trim O'Sullivan's lead to six frames.

Jamie Jones, the 24-year-old qualifier from near Neath, was faring better than countryman Williams as he moved 10-6 ahead of second-round opponent Andrew Higginson, the 34-year-old Widnes cueman.

World number 36 Jones had breaks of 95 and 101, plus a gutsy clearance of 39 to pinch the final frame, doubling in the black to open up his four-frame lead, and Carter or Trump await the winner.

Another Welshman, two-time Crucible runner-up Matthew Stevens, scored heavily at times in the opening two sessions against Barry Hawkins as he fired in three century breaks, 101, 122 and 123. However Hawkins led for much of the way and by the end of their second session the pair were tied at 8-8, with Stevens firing an 80 break in the final frame.