SHEFFIELD, April 23: Defending champion Mark Williams was struggling to find his form on Thursday as he trailed Joe Perry by two frames in their second-round match at the world championship.

Perry produced a 145 clearance - the highest break of the tournament so far - on his way to taking a 5-3 lead in the best-of-25-frames tie, which resumes on Friday.

Ronnie O'Sullivan and Andy Hicks were involved in fresh controversy when they began their second round match. O'Sullivan, who made a rude gesture during his first round clash with Stephen Maguire, picked up the last red in the third frame and conceded with Hicks on a break of 40.

Hicks, who nearly came to blows with Quinten Hann at the end of their first round tie, responded in the next frame by conceding and walking out of the arena while O'Sullivan was still at the table.

The spat appeared to motivate Hicks who won the next two frames to take a 4-2 lead. But O'Sullivan claimed the last two frames of the session to level at 4-4, finishing with a century break. Anthony Hamilton held off a determined challenge from Steve Davis to reach the second round.

Davis, winner of six world titles, fought back from 9-4 down to move within two frames of Hamilton by claiming three frames in a row but Hamilton clinched victory by winning the 17th frame. Paul Hunter was relieved to beat John Parrott 10-7 after being pushed all the way by his experienced opponent.

Hunter is now looking forward to meeting his close friend Matthew Stevens in the second round.

First round results