Stephen Maguire used to believe the hype that he was a future world champion in waiting but, after eight unsuccessful attempts to win snooker's biggest prize, the Glaswegian is adamant that he is now ready to live up to his star billing.

Maguire kicked off his world championship semi-final showdown with Englishman Ali Carter yesterday in Sheffield and, having slipped 5-3 down after the first session of their best-of-33 frame marathon, the Scot admitted: "I heard people saying that I was a future world champion a few years ago – and I believed it, to be honest. I believed in my own ability and it just never happened. Lots of people were tipping me to dominate, but it's not easy – and the world championship is not an easy tournament to win, there's a lot of great players out there. It just hasn't happened but, hopefully, this one or the next one I can get my name on that trophy."

Self-doubt crept into Maguire's game when he failed to hit the heights after winning the UK Championship, his first major title, in 2004.

Ronnie O'Sullivan tipped the world No.7 to dominate the game for years to come and seasoned professionals showered praise on the Scot but in five of those previous eight visits to the Crucible Maguire had failed to get past the second round.

"I did start to doubt myself that I could win this tournament," said Maguire. "I lost a couple of close matches here when I was playing well and thought I could do a bit of damage here.

"I lost 13-12 to Joe Perry one year after not missing a ball in the first two rounds. I was 8-0 up in the first two games I played and I fancied it that year – and, all of a sudden, I was beaten in the quarter-finals in a deciding frame.

"You start doubting yourself, you start thinking 'Can I last 17 days?' but you just keep trying."

Maguire famously squandered a 14-10 lead in a 17-15 semi-final defeat to John Higgins in 2007 and losing to his compatriot and good friend was especially hard to take.

"I was 14-10 up, but looking back on it – I've watched the match a couple of times – I wouldn't say I missed that many chances to win," added Maguire.

"I missed a pink into the middle at, I think, 14-12 and if I'd gone 15-12 up, it would have been a big gap."

O'Sullivan, meanwhile, will resume today with a slender 5-3 advantage over Matthew Stevens after the opening session of their semi-final.