Selby beat another man who has tasted glory at the Crucible – Shaun Murphy – 4-3 after coming from 3-1 down.
Selby rattled off breaks of 107, 86, and 56 to win the final three frames.
World number two Neil Robertson also came through a tough day when he had to win two 4-3 matches against Elliot Slessor and Anthony McGill in between a 4-0 romp over Jimmy Robertson.
The tournament is now at the last 16 stage and will be played to a finish on a bumper Sunday with the likes of Ronnie O'Sullivan and Judd Trump still in the hunt for glory.
Sunday's last 16 line up:
Rod Lawler v Fraser Patrick
Neil Robertson v Dechawat Poomjaeng
Mark Selby v Liang Wenbo
Robert Milkins v Mark Allen
Alan McManus v Xiao Guodong
Judd Trump v Stephen Maguire
Tian Pengfei v Ronnie O'Sullivan
Ricky Walden v Fergal O'Brien