World number seven Barry Hawkins was the biggest casualty in the first round of the World Open after falling to a final-frame defeat to Chris Wakelin.
The 38-year-old led 3-0 and 4-2 in the best-of-nine match following two half-centuries, but Wakelin hit back to grind out the final three frames to advance to the last 32.
Welsh potter Matthew Stevens also crashed out in the first round after compatriot Mark Williams completed a dominant 5-0 whitewash, which included a terrific 126 break in the fourth frame.
World number eight Neil Robertson was in imperious form with two century breaks and three 50-plus scores during his 5-1 success over Thailand's Noppon Saengkham with Ricky Walden rattling off five half-century breaks during his win against Andrew Higginson by the same scoreline.
Peter Ebdon won the battle of the former world champions as he saw off Graeme Dott in a 5-2 victory, while China Championship winner Luca Brecel joined him in the second round with a 5-1 success over Mike Dunn.
There were also wins for Ryan Day, David Gilbert, Robert Milkins, Ben Woollaston, Xiao Guodong, John Astley, Allan Taylor and Matthew Selt.
Ken Doherty and Mark Allen are both in action in the first round on Tuesday.