London: Mark Selby held his nerve to beat Australia’s Neil Robertson 17-15 in a hard-fought World Championship semi-final on Saturday.

Selby now faces two-time defending champion Ronnie O’Sullivan, bidding for a sixth world title in total, in a best-of-35-frame final that gets underway at Sheffield’s Crucible Theatre in northern England on Sunday.

It took Selby, a losing finalist against John Higgins seven years ago, some 12 hours to defeat 2010 world champion Robertson, whereas O’Sullivan had already given himself a day off by easing past Barry Hawkins 17-7 on Friday.

Heading into Saturday’s final session Selby and Robertson were all square at 12-12.

Left-hander Robertson went 13-13 up only for Selby to win four of the next five frames, with breaks of 79, 77 and 54 taking him to within sight of victory.

However, Robertson kept Selby waiting with a break of 108 — his 10th century of the tournament extending the Melbourne-born player’s record of hundreds in a professional tour season to 103. But thoughts the match might go to a deciding frame evaporated soon afterwards when Selby made a break of 74 to set up an all-English final with O’Sullivan.

“That’s got to be up there with the standard of any semi-final that’s ever been played here,” Robertson said after a defeat that saw him relinquish the world No 1 ranking to Ding Junhui, despite the Chinese player’s first-round loss in Sheffield.

“Mark’s played the best I’ve seen him play. He played some fantastic stuff.”

However, Robertson was unsure if Selby could now claim a maiden world title given O’Sullivan’s record in world finals.

“He just doesn’t lose finals,” Robertson said, before adding: “If Mark can play the way he did against me — Ronnie is more clinical than me so it’ll be interesting to see how the match pans out — then he’s got every chance of competing with him.

“So much depends on how much rest Mark can get.”

Selby, well aware of the dangers of fatigue, said: “I don’t feel too bad at the moment. I’m sure I won’t sleep because of all the adrenaline but I’m going to go out there in the final and enjoy it.

“Ronnie’s a genius and doesn’t fear anyone. He’s played some great snooker in patches and he’s missed a few balls and people haven’t punished him.

“I know I’ll get my chances, but it’s a matter of whether I take them or not.”

O’Sullivan, speaking earlier this week, hailed Selby’s battling qualities.

“Mark’s the toughest competitor on tour,” said O’Sullivan. “He can take the game at his pace and if you step up the pace he’s a player who is a predator and he can score heavily as well.”

O’Sullivan would match Steve Davis and Ray Reardon’s mark of six world titles were he to defeat Selby in a final that will be played to a finish on Monday.

Victory would leave ‘The Rocket’ only one short of Stephen Hendry’s modern era record of seven world titles.

The Scot was the last player to win three successive world titles, achieving five in a row between 1992-96.

“I’m just buzzing to be playing and enjoying it,” O’Sullivan said after his win over Hawkins.

“To get to three finals in a row having already won two — if you’d have told me that three years ago it would’ve never entered my thoughts I could do it.

“I’ve still got one more match to play so I can’t afford to get all excited.”