Wu Yize and Mark Allen have contested the longest frame in Crucible Theatre history during their World Championship semi-final, a 100 minutes and 21 seconds epic that was described variously as “horrendous” and “an embarrassment to snooker”.

Chinese star Wu, 22, competing in the last four for the first time, saw his five-frame lead disappear at the outset of the second session, as Allen recovered from 6-2 down to lead 7-6, before the pair became locked in an interminable 14th frame.

A 55-minute period passed without a ball being potted, as eight reds were left covering the black over the bottom right corner pocket.

Leading 43-13, Allen, whose earlier five-frame run featured breaks of 145 and 121, refused to re-rack. The impasse eventually ended after the Northern Irishman fouled and nudged in the black, allowing Wu to claim his only frame of the session.

The frame lasted nearly 15 minutes longer than the previous record time of 85 minutes and 22 seconds, set in a 2022 World Championship second-round clash between Mark Selby and Yan Bingtao.

“In a nutshell that frame is an embarrassment to snooker, and the referees’ and the players’ association need to try to work out a way so that never happens again,” said six-times world champion Steve Davis.