Ronnie O’Sullivan made his return to snooker and secured a one-frame lead over Ali Carter after the opening session of their World Championship first-round match.

O’Sullivan, 49, had not played competitively since January when he snapped his cue and threw it in the bin following four losses in five matches at the Championship League event.

He subsequently withdrew from a number of tournaments, including the Masters, the Welsh Open and the Grand Prix, saying he “needed to prioritise his health and wellbeing”.

But the seven-time world champion recovered from losing the opening frame to take a 5-4 advantage, needing five more frames for victory when the match resumes on Wednesday afternoon (14:30 BST).

He hit a break of 107 to move 3-1 in front with the 1,283rd century break of his career and his 208th at the Crucible. He had a chance for another century, only to falter at 85 after missing a red into the middle pocket.

O’Sullivan looked on course to gain a 6-3 advantage, but missed a long red when 46-5 ahead, with Carter recovering to take the last frame of the session.

Before the tournament, O’Sullivan told BBC Sport “to come here is an achievement in itself for me” as he documented his mental health struggles.

No player has won the world title on eight occasions, with O’Sullivan aiming to move clear of Stephen Hendry’s seven successes.