Mark Selby gave himself a great chance of reaching the World Championship semi-finals after dominating the opening frames of his quarter-final tie against Mark Williams.

The three times world champion holds a 6-2 advantage against the Welshman after producing a brilliant spell of dominating snooker at the Crucible on Tuesday which he produced a potting success rate of 97 per cent.

Previously Selby thrashed Kurt Maflin 10-1 and beat Mark Allen 13-7 to get to the quarter-finals of snooker’s biggest competition.

However, Ronnie O’Sullivan still believes Selby could come unstuck against a Judd Trump or Neil Robertson should he progress to the final.

Trump and Robertson currently remain in the bottom half of the draw meaning Selby could face them, but not until the final.

O’Sullivan, who lost in the second round to Anthony McGill, said Selby may have a “decision to make” should he go on to beat Williams later today.

“He’s obviously in great touch,” he said when discussing his match on Eurosport.

O’Sullivan was then asked if Selby was one of the favourites given his hot streak of form so far.

“It’s weird because if he goes out and plays the way he has done now against a Trump or Robertson – is he as good at that fluent style as them? Results suggest not.

“Robertson’s got the better of him in the last four of five times and Trump seems to have got the better of him last four or five times – so when he plays like that against them players, they will prefer him to play that type of game.

“So does he then have to back off a bit and go a bit more granite to get a result against them? If he’s going to go toe to toe with them over two days you’ll have to say them two are the favourites.

“So he’s got a decision to make – it’s ok against these type of players. I’m not saying Mark Williams isn’t a great player but he’s 45, probably past his best and trying to enjoy it more than anything but Selby really wants to win a world title so its a different mindset.

“Results show he’s ended losing quite badly to those players (Trump and Robertson).”