Yan Bingtao produced an impressive second session to level his World Snooker Championship quarter-final against Mark Williams ©Getty Images

Masters champion Yan Bingtao and three-time world champion Mark Williams are deadlocked at eight frames apiece heading into the final session of their World Snooker Championship quarter-final at the Crucible Theatre in Sheffield.

The last eight matches got underway today, with Wales’ Williams dominating the opening session of his quarter-final, as he opened up a 6-2 advantage thanks to a top break of 106.

In the second session, Bingtao of China bounced back reducing the gap to 7-6 with a break of 103 and levelling the match at 7-7 after winning a 49 minute 14th frame.

After missing a black off the spot in frame 15 Bingtao took the lead for the first time in the match, before Williams took advantage of his opponent missing a black to clear and level the match heading into tomorrow’s scheduled final session.

England’s Ronnie O’Sullivan’s quest to earn a record-equalling seventh World Championship title continued against Scotland’s Stephen Maguire, with O’Sullivan opening an 11-5 lead after two sessions.

Despite experiencing trouble with his cue tip in frame two, O’Sullivan claimed six successive frames, including a top break of 123 as he surged into a commanding lead of 6-2 after session one.

O’Sullivan dominated session two of their quarter-final once Maguire had cut the gap to 6-4, opening up a six frame overnight advantage of 11-5, with a run that included a break of 94, missing a pink for a century.

The other two quarter-finals completed their opening session today, with four-time world champion John Higgins of Scotland leading England’s Jack Lisowski 5-3.

Lisowski won the opening frame with a break of 98, before Higgins opened up a 3-1 lead with a top break of 91.

The session concluded a scrappy fashion, with Higgins winning the sixth frame on the final black, and ending proceedings with a two-frame lead.

Elsewhere in an all English match-up, 2019 world champion Judd Trump took a 5-3 advantage against 2015 winner Stuart Bingham.

Their only previous World Championship meeting came in 2015, when Bingham prevailed 17-16 in the last four.

This contest could be just as tight, with Trump making a top break of 105 on his way to a 4-2 lead.

Bingham reduced the gap to one with a break of 106, before Trump claimed a 35-minute final frame of the session to restore his two frame advantage.

All four quarter-finals are scheduled to conclude tomorrow.