Mark Allen and Wu Yize played out the longest frame in Crucible history during the second session of their World Championship semi-final.
A farcical 14th frame, in which eight reds were left covering the black over the bottom right corner pocket, lasted 100 minutes and 21 seconds.
It contributed to a shortened session that ended 7-7, featuring only six of the eight frames scheduled, and delayed the resumption of the other last-four match between John Higgins and Shaun Murphy.
The impasse that left the match without a ball being potted for 55 minutes - and eventually prompted referee Marcel Eckardt to warn the players - was ended when Allen fouled and nudged the black in.
That allowed Wu to pick up his only frame of the afternoon, albeit only after another 30 more minutes had elapsed.
"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-time world champion and BBC pundit Steve Davis.
In response World Snooker ruled out making changes around re-racks - when a frame is restarted because of a stalemate - and said it felt that "the rule was applied correctly" by the referee.