Ronnie O’Sullivan and Mark Allen were involved in an extraordinary heated exchange in the late stages of their Champion of Champions quarter-final clash.
The argument, which took place in the middle of their final frame, got so tense the referee Marcel Eckardt was forced to ask several times for the players to stop arguing and return to playing snooker.
Allen went on to win the match 6-3, completing a match-winning clearance just minutes after the confrontation which had been brewing for several minutes.
But after a safety battle at the start of frame nine, reigning world champion O’Sullivan then asked Allen to sit still during his shot and expressed his displeasure over the way his opponent was allegedly moving and standing in his eye line during a number of shots.
At one point O’Sullivan can be seen going up to Allen’s corner and imitating what he was doing wrong.
Allen, however. denied any wrongdoing and remain seated throughout as O’Sullivan approached him over the matter.
Play then carried on but a bad miss from O’Sullivan was punished by a determined Allen who went on to complete a 6-3 victory.
It appeared the pair did not acknowledge each other when leaving the arena when the match finished.
Allen will face world number one Judd Trump in the Champion of Champions semi-final on Saturday.
The other semi-final will be between Mark Selby and Neil Robertson on Friday night – a repeat of their World Championship quarter-final in August.