Ronnie O'Sullivan appeared to deliberately barge into Ali Carter as the five-time winner crashed out of the World Championship in a bitter 13-9 defeat on Saturday.
O'Sullivan snapped in the 19th frame of the second-round match at Sheffield's Crucible Theatre.
The 42-year-old had just fluked a snooker when he and Carter collided at the side of the table in a flash point that defined the match.
Carter walked away without reacting and had a slight smile on his face.
But once back in his seat, O'Sullivan was heard to tell Carter: "That's for being Mr Angry."
He followed that jibe by telling Carter it was his turn to play, sparking Carter to respond: "Thank you very much, very nice of you."
"Stop being angry then," said O'Sullivan, whose shock defeat leaves him without a world title since 2013.
Referee Paul Collier intervened and said: "Right fellas, just play on", with O'Sullivan then saying he was "cool as a cucumber".
O'Sullivan trailed 11-9 at the mid-session interval, but he had been off his game for most of the match and was unable to fight back.
Carter's acrimonious triumph earned him a quarter-final meeting with Mark Williams or Robert Milkins.
Carter, who has twice overcome cancer and suffers from Crohn's disease, admitted he was determined not to let the slanging match with O'Sullivan distract him from finishing off the win.
"I just thought, 'Listen, I'm not intimidated by Ronnie like a lot of other players are, I've been through harder things than that in my life'," he said.
"He barged me, but I'm sorry, I'm not going to be bullied by anyone.
"It would have been easy for me to sit back in my chair and be like, 'I'd better be the little boy in the corner'. But no, it was my day today and I'm delighted."
O'Sullivan was asked whether he would apologise to Carter.
"I don't think there's anything to apologise about. There's no hard feeling there," he said.
Asked if he thought he might be fined by disciplinary chiefs, O'Sullivan added: "I don't really know. They can send a letter to my lawyer and they can happily deal with it.
"Have you never been angry in your life? We all get angry sometimes. If someone's going to shoulder-barge into me, do I have to walk around him, tiptoe or do a little curtsy as if he's the Queen? Sometimes you have to stand your ground. I'm not a limbo dancer you know."
Britain's Ronnie O'Sullivan, pictured in 2017, snapped at his opponent in the 19th frame of the second round match at Sheffield's Crucible Theatre