Five-time world snooker champion Ronnie O'Sullivan displayed a typically assured break-building masterclass to open a three-frame lead on David Gilbert midway through their first round match at the Crucible.

Gilbert was priced as a 10/1 rank outsider to see off the world Nnumber 6, but showed reputations do not faze him when he won the opening frame.

But when your opponent is at the table there is simply nothing that can be done and breaks of 72, 84 and 71 saw the Chigwell star build a 3-1 lead at the interval.

At that stage his pot success rate stood at 96 per cent with the 'Rocket' displaying the kind of early authority that has seen him reach the quarter-final stage or better in 11 of the last 12 years.

Gilbert was not prepared to go quietly though, and emerged from the dressing room to make a nerveless 91 to win frame five.

He was then shown the cost of failing to take your chances against the five-time champion. After building a 56-point lead, O'Sullivan, quick as a flash, cut the deficit to 13 with a solitary red remaining. And, after forcing a mistake with a snooker, he cleared the table to reassert a two-frame advantage.

O'Sullivan got a taste of his own medicine in the seventh, forced to sit in his chair as Gilbert expertly amassed a 125 clearance.

Frame eight tested every facet of both players' game, and their respective responses were superb.

After Gilbert's break of 48, O'Sullivan came back to within one point. The pair then escaped with aplomb from several of each other's snookers.

But it was Gilbert who blinked first and O'Sullivan took the frame to ensure an overnight lead.

And a 71 to finish off puts the 40-year-old in command ahead of tomorrow morning's conclusion.

Watch the World Championship LIVE on Eurosport, with Colin Murray and analysis from Jimmy White and Ronnie O’Sullivan.