Selby’s credentials are well established. As a multi-title winner at this event, the World Championship and the Masters, nobody would be surprised to see him lift the trophy on Sunday.
Against Zhou he opened up with a 73 but was then forced to dig deep and stay focused.
The 27-year-old Zhou checked out of his hotel before achieving a last-32 win over Ronnie O’Sullivan, such were his low expectations for that match.
A repeat performance against Selby was a tall order, but Zhou delivered the highlight of the evening with a sublime run of 132 to go 2-1 ahead.
Selby went 62 minutes and 50 seconds without potting a ball at one point before getting back to 2-2.
From that point onwards, the Leicester man took complete control.
He jokingly looked at his watch after winning a prolonged fifth frame that lasted over 53 minutes before knocking in runs of 71, 75 and 56 to set up a last-eight meeting with Elliot Slessor or Barry Hawkins.
“At 2-2 I was over the moon. After 3-2 I felt like I controlled the match and played some decent stuff,” Selby said.
While Zhou this time could check out of York for another year, his Chinese compatriot Pang remains in the hunt.
Pang, who lost 6-1 in his only previous meeting with Welshman Williams, was given a standing ovation after rounding off his win this time with a superb break of 116.
After the players split the opening two frames, the 25-year-old from China won the next three.
Williams, who made two centuries, briefly rallied to get back to 4-3, but the 50-year-old inadvertently knocked in a red while potting the pink to hand his opponent the advantage in the next, and was then punished for missing a long red in the ninth frame.
“I played pretty poor. That’s how it is now – I either play well or terrible,” said Williams.
“I have no grumbles. He was the better player.”