Mark Selby has control of the battle of the three-time champions after establishing a 6-2 advantage in his quarter-final with Mark Williams at the Betfred World Snooker Championship.

Selby won the opening two frames in Sheffield without conceding a point, including a superb break of 121, and led 3-1 at the mid-session interval thanks to a pot success rate of 99 per cent.

A knock of 60 from Williams – whose first pot of the match was a five-ball plant in the third frame – had reduced the deficit before the break but his opponent's dominance continued after the restart.

Selby came from 55-6 down to take frame five and then produced breaks of 90 and 76 to make it 6-1, before Welshman Williams gave himself overnight hope by ending with a superb run of 111.

On the other table, there was little to separate world number one Judd Trump and Shaun Murphy as they finished the day locked at 4-4.

Neither player was able to move more than one frame in front during an evenly-matched opening session at the Crucible.

Trump, winner in 2019, produced breaks of 87 and 68 either side of knocks of 80 and 79 from 2005 champion Murphy in a rapid opening to the contest.

Errors crept in as the match became slightly more scrappy after the interval, with Trump's 105 in frame seven – the 79th century of this year's tournament – the highlight, before a 67 from Murphy left proceedings tantalisingly poised.

Earlier in the day, 2010 champion Neil Robertson recorded two centuries as he established a 5-3 lead over Kyren Wilson.

Breaks of 100 and 105, along with an extraordinary fluke on the blue in the fifth frame, helped Robertson into a 4-1 lead before Wilson reduced his deficit with a break of 76.

Robertson took a lengthy seventh frame before last year's runner-up Wilson claimed the last of the session following confusion over whether he was 67 or 65 in front when he ran out of position with five reds remaining.

With referee Jan Verhaas establishing that Wilson was 65 points ahead that meant Robertson had the opportunity to snatch victory with a clearance, but the left-handed Australian crucially missed a long blue into the corner pocket.

Stuart Bingham and Anthony McGill were locked together at 4-4 following their first session, 2015 champion Bingham recovering from 2-0 down with the aid of two centuries.

Bingham was so frustrated at missing a red while on a break of 60 in the third frame that he almost punched the table, but McGill was unable to take advantage and Bingham won the next with a break of 64 and recorded the 500th century of his career with a 122 clearance to lead 3-2.

A 64 break from McGill, his highest of the session, levelled the scores and after Bingham edged in front with a run of 108, the Scot won the final frame of the session to keep the contest finely poised.

Robertson versus Wilson and Bingham against McGill resume on Tuesday evening, while the other two best-of-25 frame matches continue on Wednesday.