The former Troon Welbeck player triumphed in the bunkered-sponsored circuit’s fourth event of the campaign at Prestwick St Nicholas with a six-under-par 63.
In a bogey-free effort, Stewart illuminated his round with an eagle-2 at the 17th and also had four birdies on his card.
He won by two shots from host club amateur Sean Addie and fellow Ayrshire professional Jim Johnston, with Largs pro Anthony O’Donnell a further shot back in fourth.
“I played lovely,” said Stewart, who plays mainly on the PGA EuroPro Tour. “I picked up a few birdies at some of the shorter holes then holed a pitch from 30 yards for my eagle.
“The course was in fantastic condition and this tour is brilliant. As well as being competitive, it’s very sociable and great to get a game with my golfing buddies.”
Chris Maclean has two wins under his belt, carding a four-under 68 to come out on top among 185 entries for the season-opener at Castle Stuart before repeating the feat with a seven-under 63 at Arbroath.
In between, Joe Bryce triumphed at Hayston courtesy of a three-under 67, with John Henry, the runner-up at Arbroath, the other player through to the season-ending final at Dumbarnie Links in October.
The fifth event at Blairgowrie has just started and runs until 4 July before the circuit moves on to Scotscraig.
“It was a busy couple of weeks in Scotland with the Amateur Championship, the PGA Pros and PGA EuroPro Tour all on, so to still get over 50 top amateurs and pros taking part at Prestwick St Nichola was brilliant,” said tour organiser Alan Tait, who set up the circuit last year to provide playing opportunities during the Covid-19 pandemic.
“All the players thoroughly enjoyed the challenge of Prestwick St Nicholas and we are expecting a great turn out over the next couple of weeks at Blairgowrie.
“Michael Stewart is another worthy champion as the tour continues to go from strength to strength.”