RONNIE O’Sullivan is well on course to win his fourth world title after taking a significant five-frame lead over Ali Carter in this afternoon’s penultimate session.

The Rocket goes into the tournament’s final session tonight with a 15-10 lead after extending his advantage this afternoon.

Leading 10-7 overnight, O’Sullivan made the perfect start in his quest to join the likes of Joe Davis, Stephen Hendry, Steve Davis, Ray Reardon and John Higgins who have all won at least four world championship titles. He won the first two frames to go five frames clear at 12-7. A century break in the first frame ignited the Rocket into action.

And Carter must have been a worried man after missing two golden chances to win the 20th frame. After a brave pot in the middle pocket Carter failed to take full advantage and could only make 21.

But when O’Sullivan missed a red in the bottom corner pocket, Carter was given another chance. But yet again he blew a great opportunity by missing a red with the rest when on a break of 27. Trailing 48-22 O’Sullivan refused to give Carter another chance and cleared up to take a 13-7 lead.

And Carter was in danger of losing the final with still a session to spare after going 14-7 behind. Again The Captain could have won it but missed a crucial yellow when on a break of 41.  

But things were to get much better for the world number 17 after the mid-session interval. Huge cheers were heard at the Crucible when Carter did enough to claim his first frame of the day and end any possibility of losing the match in the afternoon session.

Frame 23 saw Carter pull another frame back with his first century break of the match (105) before he won a third frame on the bounce to reduce his arrears to 14-10.

But breaks of 64 and 55 in the 25th frame saw O’Sullivan regain a five-frame advantage and be just three frames away from victory.

Credit must go to Carter for fighting back in the session but he faces one mighty challenge tonight to pull off his first world title. At 15-10 in front, O’Sullivan looks a very strong favourite.