Quite an Irish procession at the Crucible yesterday. Greenhorn Dubliner Michael Judge, 1997 champion Ken Doherty and last year's surprise package from Belfast, Joe Swail, were part of what Sheffield radio dubiously labelled a "shamrock showdown" at the World Snooker Championship.

Last year's semi-finalist Swail was pitted against number one seed Mark Williams and finished with a significant amount to do if he is to make the quarter-finals.

He finished the second session of the three-session match chasing a 10-6 deficit, leaving Williams a target of just three frames when play resumes this morning. Doherty and Judge ended their first session with Doherty, the former champion, 5-3 in front.

While either Doherty or Judge will make an exit when they finish their match today, accountant Patrick Wallace, who plays Mark King in the first phase of his second-round match this afternoon, offers a fourth Irish name capable of advancing to the quarter-final stages.

There is an unusual feel to these championships, with only a forced, uneasy truce allowing the event to run as smoothly as ever. The tension on the baize is almost light relief following the abandoned rebel tour. On the table, Doherty's match started as he had prayed it would not. Having given Judge a three-frame start in the Scottish Open two weeks ago before rallying to a 5-3 win, Doherty, despite the promise to himself that he would not repeat it, conceded the first two wobbly frames to Judge before winning five in succession.

Doherty has beaten Judge in their last two outings in Scotland and at the China Open in 2000, while Judge must go back to the British Open in 1997 for the last time he beat this tournament's seventh seed.

The consoling lead will do much for Doherty's confidence which, with two tournament wins and a place in another final, has remained high this season.

Judge's patience will be sternly tested in the remaining sessions. The prize is a quarterfinal meeting with second seed John Higgins.

Judge looked confident and more predatory than Doherty in the opening salvo but as the older player built breaks of 50, 51, 68 and 66, to go from 0-2 down to 5-2 ahead, he looked to be seamlessly taking control of the session. However, Judge finished with breaks of 53 and 41 to claim the last frame.

Williams oozed control against Swail, who was always at least two frames behind the Welshman yesterday. Williams held a 5-3 overnight lead and built it to 8-3 before Swail was allowed even put his foot in the match again.

Last year's finalist, Matthew Stevens became the first player to advance to the quarter-finals when he beat Anthony Hamilton 13-5. Stevens, who is one of the fancied players to make it to next weekend, took only 11 minutes and 21 seconds of the final session to claim the one frame he needed. Six-times winner Stephen Hendry had confessed to being frustrated with his game coming into the championships, but is happier now he is in action here. "The balls have started to go in over the last few days. It's pleasing," said the Scotsman. "The longer games (25 frames) give you time to settle down."

Ronnie O'Sullivan ended the second session of his match against England's Dave Harold 10-6.