Snooker: Ali Carter has stomach for Crucible battle Ali Carter has vowed to win his battles on and off the table as he closes in on Crucible glory. The 32-year-old from Essex yesterday seized a 5-3 lead after a scrappy opening session of his semi-final against Stephen Maguire at the Betfred.com World Championship. Cynical minds might argue the duo are fighting for the right to be beaten by Ronnie O'Sullivan in the final, with O'Sullivan - showing magnificent form this year in Sheffield - contesting the opening session of his semi-final against Matthew Stevens last night. But Carter is not taking an O'Sullivan triumph as inevitable, and despite suffering a mid-tournament setback in his struggle with Crohn's disease, the 2008 runner-up is determined it will not hold him back over the next four days. Eating a steak left Carter feeling uncomfortably bloated, a symptom of the bowel condition he has had to manage since being diagnosed in 2003. "Hopefully I can start feeling better if I stick to a lighter diet," Carter said. The problem is that you're well for a few weeks and then you start taking liberties with it. When you go to a restaurant all you want to do is eat, it's a nightmare. It's a very long match against Stephen but my problems haven't beaten me yet and they're not going to. They return today for two further eight-frame sessions, before the best-of-33 match is due to conclude tomorrow afternoon. Carter said: "I'm on a free roll now. I've been through the mill this past year, considered retirement or taking a sabbatical, and my guts have been terrible. I'm just delighted to prove to myself and all the doubters out there that I've still got it. Carter and Maguire both struggled to find the form which had carried them through to the final four, Carter having knocked out Judd Trump on the way and Maguire having ended the career of Stephen Hendry in the quarter-finals. After five frames Maguire had a highest break of just 21 yet still trailed only 3-2. He had somehow led 2-0 before Carter began picking him off. Carter fired in a 91 and eventually Maguire strung a run of 82 together, but the Scot's second highest break of the session was a mere 26, underlining his problems. O'Sullivan headed into his clash against Stevens with a phlegmatic attitude, having beaten three former world champions already in Peter Ebdon, Mark Williams and Neil Robertson. "It's nice to just enjoy the game and play it with a bit of openness, that's my natural game," O'Sullivan said. As long as I'm cueing well I feel I can be quite aggressive in the balls and that's the key, that's my game to be aggressive. I'm just pleased to have had a little run in this. If I get through another match then great, if I don't it's no big deal. I've had a good go; I've enjoyed it. If I lose my next match it's no big deal, it's just there's more to life. If it falls apart, it falls apart. What can I do about that?