Judd Trump branded Ali Carter's behaviour "childish" after being dumped out of the Betfred.com World Championship.
Last year's runner-up frittered away a 12-9 lead to lose 13-12 in the second round, the 22-year-old title favourite beaten in a Crucible classic which reached its climax in a 46-minute deciding frame.
Carter complained that Trump had all the luck in the match, and was so frustrated when he was put in a snooker behind the brown and yellow balls in the 23rd frame, seemingly by fluke, that he applauded sarcastically.
"If he wants to do that, then it's up to him, but he's 30-odd years old and it's a bit childish," Trump said.
Carter, 32, said the match proved that snooker is about more than simply potting balls.
Trump was baffled by the remark, and said: "I'm still a lot younger than him and have done a lot better, so let's just let the snooker do the talking."
Trump had been 9-7 ahead going into the concluding session of the match and almost made a maximum break in the afternoon's third frame but could not find position on a 13th red.
It put him 11-8 ahead though, and despite Carter taking the next with a 94 break, Trump soon re-established his three-frame cushion.
Carter began to eat into the lead though, and had his own maximum chance but could manage only 81. It put him back at 12-10, then Carter closed the gap further by taking a scrappy frame and drew level aided by a run of 53.
Trump missed a red with the rest to present Carter with a match-winning chance in the decider. He made 47 which left Trump needing four snookers, and remarkably he found three of them.
But Carter, fighting an ongoing battle with Crohn's disease, an inflammatory bowel condition, mopped up the colours he required to claim a hugely satisfying win.
Matthew Stevens held his nerve to fend off Barry Hawkins and edge through to the last eight.
The match was close throughout, as Hawkins refused to be shaken off.
Eventually Welshman Stevens crossed the winning line though, sealing a 13-11 success, aided by a break of 57 in a final-frame victory march, and the 34-year-old will face compatriot Ryan Day in the last eight.
"It was very tough," Stevens said. "I stuck in there yesterday after being 3-0 down. Barry played very solid in the opening few frames and I was under the cosh all the way really.
"Today was very tense, both of us kept missing the balls. it was tough but it's nice to get back in the quarter-final again."
Stevens, finalist in 2000 and 2005, last reached the quarter-finals in 2007 and failed to qualify for the World Championship in 2009 and 2010.
He was knocked out in the first round last year, but is enjoying the tournament in Sheffield this time.
Day is next, competing at the last-eight stage for the third time, having last gone so far in 2009.
"It's nice to see us back in the quarter-finals again," Stevens said.
"Ryan's had a tough time the last couple of years. It's nice to see him come back, especially with a good first-round win over Ding (Junhui).
"I'm very pleased he's got to the quarters but hopefully he won't get any further."
Although the tournament lost a crowd favourite in Trump, Ronnie O'Sullivan was not to be denied a place in the last eight as he beat Mark Williams at the Crucible for the fourth time in seven years.
O'Sullivan was outstanding on Sunday, winning six of eight frames in their middle session to build an 11-5 lead, and he finished off Williams 13-6.
Williams knew there was a danger he would be finished off quickly. He said: "I knew it was going to be hard and I'd have to win the first four frames. If you give Ronnie a sniff of a chance he just knocks in 50s and 60s in a matter of a couple of minutes. It's frightening to watch.
"It'd be excellent to see a Welshman get to a final, but if Ronnie plays anything like that, there's no one left in this competition that can give him a good run. Robertson is the only man that can give him a good run but he's just so far in front of everybody else that it's frightening."
Three-time winner O'Sullivan plays Neil Robertson, the 2010 champion, next.
O'Sullivan enjoyed the standing ovation he received after a thrilling break of 128 on Sunday, saying: "I've never had that before, apart from my 147s.
"That was a special moment there and it took me by surprise. I played a few good shots in that break and I think the crowd appreciated it. It's nice to give people something to remember. In another 50 years they might show some of those shots on YouTube, or when I'm dead and gone they'll say, 'Look at this player, see what he did'.
"It's just one of those for the memory bank, it was a special moment, a really good six frames. I was being quite aggressive and that's the way you need to play.
"I think whoever wins this championship will have to beat Neil Robertson, and I've got to play him now.
"Neil's had a brilliant season, he's won the Masters. He's a big-time player and he's proved it on the big stage."
A third Welsh player reached the quarter-finals with Shaun Murphy's first-round conqueror Jamie Jones, the world number 36, setting up a clash with Carter by defeating Widnes cueman Andrew Higginson 13-10.
Jones said: "I feel relief. I've played Ali before and I won it so hopefully that's a good omen."
Higginson said: "All credit goes to Jamie, but I'm disappointed. I've enjoyed my time here and you get a feel for the place."
All the quarter-finals begin on Tuesday, with Stephen Hendry taking on Stephen Maguire in the morning session, at the same time as the tussle between Day and Stevens on the other table.