Recent UK Championship finalist Judd Trump secured a 4-3 victory over Mark Williams to move into the last 16 of the Lisbon Open, but Ricky Walden suffered a surprise deciding frame loss to Ryan Day.
Trump won his first two matches against Tom Ford and Thepchaiya Un-Nooh without dropping a frame, before edging a much tighter affair with Williams to set up a fourth round meeting with India's Aditya Mehta, who dropped just two frames in his opening three matches.
Matthew Selt capitalised on Walden's defeat, with victories against Michael Tomlinson and Graeme Dott, before beating Day in the third round with a 4-2 win. Selt's next opponent will be Dominic Dale, who whitewashed Marco Fu and lost just one frame against David Gilbert, en route to the last 16.
World number five, Barry Hawkins, returned to form after a disappointing UK Championship, seeing off Chris Norbury, Rory McLeod and Andrew Higginson. Hawkins is due to play former world champion Peter Ebdon next, after he progressed swiftly, losing only four frames in his three matches.
Elsewhere, Joe Perry completed wins over Zhang Anda, Fergal O'Brien and Jamie Rhys Clarke, as he booked a fourth round match with Welshman Jamie Jones. A former world quarter-finalist, Jones has struggled of late, but produced an impressive string of performances, which included 4-1 dismissals of Jimmy White and Xiao Guodong.
Seeking a third successive European Tour title, Shaun Murphy begins his tournament on Saturday against Craig Steadman. Assuming he progresses, his other likely opponents are Kyren Wilson and Jack Lisowski, before a testing last 16 encounter with Stuart Bingham.
Stephen Maguire starts his campaign against Englishman Sanderson Lam in a section of the draw that could see him play countryman John Higgins in the fourth round. Lukas Kleckers will be Higgins' first round challenge.
In Saturday's other selected match-ups, Matthew Stevens plays Alfie Burden, Jak Jones takes on fellow youngster Joel Walker, and 19-year-old Belgian Luca Brecel faces Ratchayothin Yotharuck.
The Lisbon Open marks the first time professional snooker has been played in Portugal.