Judd Trump, Neil Robertson, Stuart Bingham and Mark Allen all made further progress on day 3.
Selby had a failed try at a 147 as he beat Gary Wilson 4-1.
John Higgins and Mark Williams both won meaning they will play each other in the next round.
Ronnie O'Sullivan, Stuart Bingham and Judd Trump also through.
Ronnie O'Sullivan is out after a 4-3 defeat to Yan Bingtao in a high quality contest.
John Higgins came from 0-3 down to beat Mark Williams 4-3.
Also through to the last 8 are Shaun Murphy and Mitchell Mann.
In the evening session Judd Trump won 4-3, Mark Allen also won 4-3.
World champion Mark Selby is out though after a 4-2 defeat to David Gilbert.
Ricky Walden won a late night final frame decider to beat Jackson Page 4-3.
Ricky Walden overturned Shaun Murphy (only metaphorically, alas), to reach a semi-final with Mark Allen, who was similarly impressive in beating Judd Trump from behind.
Yan Bingtao trounced Mitchell Mann 5-0.
John Higgins claimed a 5-3 victory over David Gilbert.
Poor Dave led 2-0, but in the interval at 2-2, Ronnie was basically suggesting he had no chance. At least there's a good chance of a new HN winner (think Higgins might have won the Welsh one or something).
Allen comfortably beat Walden 6-3.
It will be John Higgins to play Mark Allen in the final after the Scot eased past Yan Bingtao 6-2.