Joe Swail's 5-4 win over Stephen Maguire in the Welsh Open at Newport earned him his first ranking semi-final appearance since October 2001 and frustrated the world No2's opportunity to make significant inroads on Ronnie O'Sullivan's commanding lead at the top of the rankings.

Following his 5-4 win over Ding Junhui from the unpromising position of 2-4, 0-69, Maguire almost managed another remarkable recovery from 4-2 adrift.

At 4-3 Swail led by 23 with only 18 on the table but unluckily ran in-off in escaping from a snooker. Maguire cleared the last three colours to tie and added the tie-break black with a corner pocket double.

Swail, who had pulled a muscle in his cue arm in the sixth frame, making him wary of certain shots, took four scoring visits to lead 43-0 in the decider.

There was nothing in it, though, by the time Maguire, escaping from a fluked snooker on the brown, instead clipped the blue in to allow the Northern Irishman to pot brown, blue and pink to reach the 10th ranking semi-final of a 17-year career which has yet to provide him with a title.

"It was very exciting for the spectators," Swail acknowledged. "But it was a different sort of excitement to the likes of O'Sullivan, because I was twitchy. I'm not used to this after all these years and, with the bad luck I had, I just couldn't seem to get over the line."

Maguire confessed to feeling surprisingly "flat" for a quarter-final, perhaps a consequence of the 10am start. "To be 3-1 down with the sort of chances I had was disgraceful."

Allister Carter, whose long potting these days is the most consistent on the circuit, reached his fourth semi-final of the season from six attempts by beating Shaun Murphy, winner of December's UK Championship, 5-2.

Consecutive frame-winning breaks of 74, 73 and 62 to lead 3-1 were the core of a performance which suggests that he is in the form which may secure him his first title this week.