World number one Selby was never in his contest against Perry, who made one century - in the final frame - of a dominant 4-0 triumph in Newport.
Number two Trump meanwhile fought from 3-1 down to beat Dale 4-3.
After taking the opener a nerveless long red sealed the second frame for Dale and dispirited Trump, who had found the three snookers he needed to remain in it.
Trump won the third but Dale gave Trump little chance with a 114 in frame four.
Dale, ranked 20th, had chances to seal the win in frames five and six but failed to capitalise and Trump regained his fluidity to take three on the trot - the final frame containing a half-century - and claim an unlikely victory.
World number 14 Ricky Walden was knocked out 4-1 by 27th-ranked Tom Ford while Ding Junhui eased past Mark King.
There was another surprise exit in the evening session, as twice world champion Mark Williams appeared to suffer the effects of spending the day in hospital as he awaits the birth of his third child.
Williams was outplayed by Robert Milkins, who won 4-1 after two half-century breaks and an 87.
Graeme Dott took a 4-2 win over Fergal O'Brien with top breaks of 50, 63 and 68.
Round one results
Tom Ford 4-1 Ricky Walden
Judd Trump 4-3 Dominic Dale
Ding Junhui 4-0 Mark King
Andrew Higginson 4-2 Michael Wasley
Stuart Bingham 4-0 Craig Steadman
Joe Perry 4-0 Mark Selby
Robert Milkins 4-1 Mark Williams
Graeme Dott 4-2 Fergal O'Brien
Last 16 draw
Doherty v Ford
Dott v Advani
Not before 1.30pm
Maguire v Stevens
Robertson v Bingham
Not before 2pm
Trump v Higginson
Ding v Allen
Not before 7pm
Milkins v Baird
Perry v McManus