The opening session of the World Snooker Championship final was marred with controversy as Ronnie O'Sullivan was warned for lashing out at the referee.
The 46-year-old ended up leading the opening session 5-3 despite going behind to opponent Judd Trump early on.
O'Sullivan stormed in front by winning five consecutive frames, before Trump started to cut out some nervy mistakes.
The drama peaked during the eighth frame, when O'Sullivan failed to get out of a snooker. Referee Oliver Marteel suggested that he made an obscene gesture afterwards, which led the Brit to challenge to official and check camera footage.
"I just think he (Marteel) seems to be looking for trouble. I just get that vibe from the guy," said O'Sullivan.
"They've got hundreds of cameras out there and they can go and check them all. I'm not going to have any of it because I think he's just trying to create something. He needs to deal with it, not me."
World Snooker Tour confirmed that the incident had been noted, and they have since released a statement confirming he had been warned:
"Ronnie O'Sullivan received a formal warning from the referee following a gesture he made in the eighth frame."
O'Sullivan is already facing an investigation by the WPBSA disciplinary committee for allegedly making a lewd gesture after missing a black in the 13th frame of his 10-5 first-round win over Dave Gilbert.
If the following three sessions are as action-packed as the first then the final will live up to the high expectations, and with both players making a solid start to the showpiece, Monday evening's conclusion is bound to be entertaining.