Mark Selby has control of the battle of the three-times winners after establishing a 6-2 advantage in his quarter-final with Mark Williams at the World Snooker Championship. Selby won the opening two frames in Sheffield without Williams scoring, including a superb break of 121, and led 3-1 at the mid-session interval thanks to a pot success rate of 99%. 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 Williams gave himself overnight hope by ending with a superb break of 111. On the other table, there was little to separate the world No 1, 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, the winner in 2019, produced breaks of 87 and 68 either side of knocks of 80 and 79 from the 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. Anthony McGill moved to within four frames of a second successive semi-final appearance by hitting back to gain the upper hand on Stuart Bingham. McGill, conqueror of the defending champion, Ronnie O’Sullivan, in round two, registered two century breaks in a high-scoring second session en route to establishing a 9-7 overnight lead over the 2015 winner. Resuming with the scores locked at 4-4 from Tuesday’s opening exchanges, the Scot dropped the opening two frames of the evening but swiftly recovered to impressively take five of the final six. The 30-year-old made breaks of 126, 83, 92, 130 and 75 to put himself in pole position for another last-four appearance in Sheffield, while Bingham’s 120 in frame 13 – his third century break of the match – gives him some hope of a comeback. Neil Robertson’s quarter-final clash with Kyren Wilson is tantalisingly poised at 8-8 following two captivating sessions. Robertson carried a 5-3 lead into the evening and the momentum continually shifted during an engrossing display of impressive pots, inventive safety and unexpected misses. Wilson edged the opening frame of the second session on a respotted black and then won two of the next three to pull level at 6-6 going into the interval. A break of 126 put the 2010 champion, Robertson, back ahead but, after Wilson subsequently came from 50-0 down to level at 7-7 and then moved into the lead for the first time, he was required to dig in to keep pace in a helter-skelter encounter which resumes on Wednesday morning.