The Englishman registered ten birdies and an eagle in a stunning 60 that moved him to 12 under and left everybody else playing catch up at Chervò Golf Club.
Placing on the fairways meant that he could not set a course record but Canter's remarkable effort was still the lowest in event history since 1972 and matched the lowest score to par ever recorded on the European Tour.
Canter made his European Tour debut as an amateur at the 2010 Open Championship but it would take him five more years to earn his card at the Qualifying School.
Successful returns to the Q School followed in 2016, 2017 and 2019 and, at the 78th of time of asking, he recorded a first European Tour top ten at this season's Hero Open.
He has recorded two more since - including a second placed finish at the Portugal Masters - and while Canter is now beginning to establish himself on Tour after almost a decade as a professional, he is refusing to get carried away.
"Winning, you need a lot of things to go your way," he said. "Portugal, I felt like I did about as well as I could that week and came second. I’ve had other weeks where I’ve felt the same and come tenth, so the standard is good.
"So for me to win, and for me to say I feel ready to win, I feel like I’m jumping the gun. You play as well as you can for four days and hopefully it’s your week. You do need things to go your way, I feel, to win."
Starting at the tenth in just the second group of the day, he sandwiched gains on the 14th, 16th and 17th by taking advantage of the par five 11th and 18th to turn in 31.
You play as well as you can for four days and hopefully it’s your week. You do need things to go your way, I feel, to win
He made further birdies on the third and fourth but jumped clear of the pack on a low scoring morning with an eagle on the sixth after putting his second to 16 feet.
A birdie from five feet at the seventh was followed by a poor tee shot at the next but he played a wonderful second to set up another gain from 20 feet.
An approach to 15 feet on the ninth then set up a closing birdie and a second nine of 29 as he picked up five shots in his last four holes.
"It feels great," he said. "The score, days like that, the back nine there, everything’s gone in. I gave myself some chances and it was just one of those days where you’ve just got to enjoy the ride.
"I think it’s playing quite long and it definitely helps being able to hit it straight and that’s something I’ve been able to do most of this year so far.
"I like the golf course but I think obviously a lot of things have gone right today to help me shoot that."
Hansen made a hat-trick of birdies from the tenth and while he dropped a shot on the 14th, he made gains on the 15th and 17th to turn in 32. Another trio of gains came from the fifth and a 25 foot putt on the ninth moved him into solo second.
He was joined by Burmester late in the day as the 31-year-old made three in a row from the 11th and added further gains on the 17th and 18th before eagling the short par five sixth and holing from 17 feet on the next.
Bland, Lengden and Perrier were bogey free with seven birdies, Besseling dropped a single shot in his round, and Arnaus made an eagle and seven birdies to go with two bogeys.
Scott Jamieson made the 19th hole-in-one of the season when he holed a six iron from 191 yards on the second.