The five-time world champion started in blistering fashion with an opening break of 72 and followed it up with 118 to go into the interval with a 3-1 lead.
After the break The Rocket quickly finished off his opponent with breaks of 101 and 71 and will now meet Judd Trump or Mark King in the quarter-finals at Venue Cymru.
"It's a nice event, but I've got to get out of Llandudno for a few days. It's a bit windy, there's not much to do around here," said O'Sullivan on ITV4.
It was a similar story for Anthony Hamilton, who knocked out fourth seed Stuart Bingham. Hamilton, recent winner of the German Masters, reeled off a 131-break first up on his way to a 5-1 victory.
Further breaks of 105 and 59 to secure a meeting in the last eight with Ding Junhui or John Higgins.