And another stirring recovery materialised today as the 16th seed hit back from 10-6 down overnight to 11-9 as he benefited from the confidence crisis afflicting the world number one.

Swail, known as the Outlaw, shared today’s first two frames with Williams and knocked in a break of 77 to trail by three.

Then came the stroke of outrageous good fortune which led to Swail snatching the last frame before the mid-session interval - one he really should have lost.

Williams was 34 points ahead but clearly struggling with his game and after one poor attempt to lay a snooker he laughed, looked up at someone in the audience and uttered some choice words about the state of his play.

His misery was then compounded when Swail, attempting a long pot on the last red, missed by a country mile but the ball cannoned into the pink and rolled into a middle pocket.

The Manchester-based player, a semi-finalist last year, held his nerve to clear the colours and then bounded up the steps to the dressing room, clearly knowing he had put the Welshman under real pressure.

Williams will have been delighted by the timing of the 15-minute break and while he was still favourite to progress, Swail’s reputation for fighting back must also have been in his mind.

On the other table, 1997 champion Ken Doherty won all four frames before the interval against his fellow Dubliner and practice partner Michael Judge to ease into a 9-3 lead.

The 31-year-old knew that if he could whitewash Judge in the session, he would avoid having to return tonight to finish off the job.