Mattmu sprang as 25-1 surprise on just his second comeback run following an unsuccessful spell at stud by making virtually all the running in the William Hill Great St Wilfrid Handicap at Ripon.
A dual Group winner early in his career, Mattmu could not attract any mares so was put back in training with Tim Easterby.
Having had the cobwebs blown away at Doncaster just two weeks ago, Mattmu showed he retains plenty of ability with a convincing success.
David Allan had the five-year-old quickly out of the stalls and made a beeline for the far rail.
Mattmu kept up the gallop to score by three-quarters of a length from from Pipers Note, with Shanghai Glory third on the near side and Snap Shots fourth.
Easterby said: "You wouldn't believe it but he couldn't get one mare at stud in Malton - not one.
"He'll go back to stud and we might send him to Ireland as he always ran well over there.
"I wasn't 100 per cent confident he was right enough to win. I'd been building him towards Ayr but the simple fact is he was a Group horse in a handicap.
"He doesn't need soft ground. Good ground is fine for him but he doesn't like Ascot. We've mucked him up before taking him there.
"It will be the Ayr Gold Cup next and then we might take him to France before he goes back to stud."
Allan said: "He's a hard horse to judge at home because he's lazy.
"I had the choice of which side to go as I was drawn in the middle.
"But even though it looked like there was a bias in the consolation race, I was on the far side and there was just no pace so I didn't think there was much in it."