A birdie at the 18th would have given him a round of 59 but he bogeyed after finding a greenside bunker.

It is the perfect preparation for the US Open, the third men's major of the year, which begins on Thursday.

"I just got it going out of the gates," said McIlroy. "I said at the start of the day I wanted to be aggressive."

Speaking to Sky Sports, he added: "I played with so much freedom over the weekend, more freedom than I've had for a while, which is exciting.

"To get a win going into next week is huge."

Fellow Northern Irishman Graeme McDowell has qualified for the Open Championship at his home course of Royal Portrush in July after finishing tied eighth on 10 under, alongside England's Danny Willett (67).

McDowell did it in style, too, holing a 30-foot putt for par on the 18th and a round of 68.

The leading three finishers in the top 10 in Canada who had not already secured Open spots qualified for the final men's major.

McIlroy's victory - seven shots ahead of Webb Simpson (68) and Irishman Shane Lowry (67) - is the largest margin of victory at the tournament since American Johnny Palmer won it by 11 strokes in 1952.

He is only the seventh golfer to complete the triple crown of victories at the Canadian Open, US Open and Open Championship - the three oldest events on the tour.

McIlroy hit five birdies on the front nine, before four more followed in succession from the 11th hole. He then made an eagle on the par-five 17th, sandwiched by two bogeys.

Dustin Johnson finished tied 20th on seven under after a 69, while world number one and defending US Open champion Brooks Koepka was on two under following a 70.