Judd Trump had the Crucible crowd in hysterics on Wednesday as he played a joke on referee Ben Williams during his quarter-final clash against Stuart Bingham.
Trump was trailing 8-6 in his bid to reach the last four, but had already secured the 15th frame when an errant positional shot left him snookered on the brown.
As someone coughed in the crowd, Trump alerted the referee to a distraction, before quickly moving the pink with his hand and taking the shot on the brown while Williams had his back turned.
Those in attendance in Sheffield burst out into laughter as the referee realised what had happened, and Trump returned to his seat with a cheeky smile on his face.
It was the second frame in a run of eight in a row for Trump as he overturned an 8-5 deficit to run out a 13-8 winner and book his place in the last four, where will face Welshman Mark Williams in the iconic one-table setup.
World No.4 Trump said: “In the end it was comfortable - but at one point this morning I was really struggling and thinking about going on holiday. But Stuart's miss on the black at 8-5 gave me confidence."
Trump is bidding for a second world title having lifted the crown at the Crucible back in 2019.
Williams won the last of his three championships in 2018, while Ronnie O'Sullivan is also through to the semi-finals.
The Rocket would draw level with Stephen Hendry on seven world titles if he triumphs in Sheffield, having booked his place in the last four by winning the two frames he needed against Stephen Maguire in double-quick time on Wednesday morning.
Speaking to former rival Hendry on the BBC following his win, the mutual respect was there for all to see, as O'Sullivan insisted he is not in the same bracket as the Scotsman.
"Stephen is an all-time legend for me, the greatest player," he said. "He was the Tiger Woods of snooker. Me, John (Higgins) and Mark (Williams) have all done well, but when he was flying he was a superstar.
"When there's three of us, we're not superstars. But when there's one man dominating the sport like he did, like Tiger Woods, it's a different level."
Williams, meanwhile, became the oldest Crucible semi-finalist for 37 years, and admitted he had felt every one of his 47 years during his 13-11 win over Yan Bingtao.
“It was a great match to be involved with.," he said. "And I am playing as well as I ever have. I did flag a bit on Tuesday night, playing two sessions in a day took it out of me and I had nothing left – that must be age.
“I was 6-2 ahead early on, but that is nothing with matches of this length – and they were two great breaks at the end under extreme pressure from 11-11.
“I feel I deserved that one, because a lot of the close ones this season have gone the other way. But I feel here as if I am playing as good as I have all season.
“And with the one-table set-up now in the semi-finals, this is the best venue in the world. I am loving every minute, and am playing some good stuff.”