The two Scots traded the opening four frames before Maguire constructed a tournament-high break of 142 on his way to taking a 5-2 lead at the Barbican Centre.
Higgins made 77 in one visit to pull a frame back, but Maguire went on to take the next to secure his fifth successive win against his good friend and compatriot and advance into the last eight.
Maguire told reporters: "It's a great win, any time you beat John Higgins is a proud moment.
"I felt good after the interval. I should probably have been 3-1 up, maybe even 4-0, and at two each I was thinking 'have I given it away?', but I was happy how I knuckled down after the interval."
Maguire won the UK Championship in 2005 with an emphatic 10-1 triumph over David Gray in the final.