The 32-year-old world No.5 has not won a first-round tie at the Masters in the past three years but he had breaks of 112, 80 and 56 on his way to a 5-1 lead. Perry battled back to 5-4 but could not carry the match into a deciding frame.
Maguire's win sets up a quarter-final against either Neil Robertson, the reigning UK champion, or Mark Allen, who meet today. "I was just glad to get through," he said. "There was bit of pressure on me towards the end but I played a decent last frame. I've changed a couple of things before coming here, so it probably was a bit of a gamble. It feels pretty good."
Earlier, the in-form Marco Fu knocked out Judd Trump 6-5. The left-hander looked close to his free-flowing best but he could not shake off a determined Fu who held his nerve in a final frame.