China's Yan Bingtao knocked out defending champion Mark Selby of England ©Getty Images

Yan Bingtao of China knocked out defending champion Mark Selby of England at the World Snooker Championship in what was a match that saw the longest frame in Crucible history.

The 22nd frame lasted 85 minutes and 22 seconds, beating the previous longest by 5 minutes and 51 seconds.

Yan is set to face Mark Williams of Wales in the next round after a 13-10 win over Selby.

It has been a difficult season for Selby who has been battling mental health issues.

While Selby had a good chance to make a dream start on Saturday, he missed a straight pink, which Bingtao capitalised on.

The final frame saw both the players miss easy pots but Bingtao triumphed eventually.

Meanwhile, Ronnie O’Sullivan of England won the only frame he needed to register a 13-4 win over Mark Allen of Northern Ireland to reach the quarter-finals for the 20th time.

O’Sullivan will run into Stephen Maguire in the quarter-finals after the Scotsman got the better of Zhao Xintong of China.

Magurie, who lost four of the first five frames, made the most of a borrowed cue to find a break of 59, that helped him seal a 13-9 win over Xintong.

Neil Robertson of Australia and Jack Lisowski of England finished at 4-4 before they return on Sunday.