The Newcastle player beat Ross Cameron (Saltire Energy) in a play-off to claim the £1800 top prize after the pair finished locked together on two-round totals of 136, eight-under-par.
They halved the 18th in par-4s at the first play-off hole then played it again, with a par proving good enough for Cowan this time as Cameron’s second putt horseshoed out.
“I was always going to play this particular Optical Express Tour event due to the fact I had played here before for Northumberland in matches against Lothians,” said the 31-year-old.
“While I wouldn’t exactly say I know the course well, there’s no doubt that helped me over the last two days.”
Two behind overnight leader Greig Hutcheon at the start of the day, Cowan looked to have dented his title hopes after dropping a shot at the third. But he covered the remaining 15 holes in five-under – three of his birdies came in the last five holes – for a second successive 68.
It was his second win in quick succession on the Tartan Tour, having already triumphed the week before in the Parkdean Pro-Am at Ayr Belleisle.
Turnhouse pro Scott Grieve (71) and Archerfield’s Elliot Saltman (66) shared fourth spot on 138, one ahead of both West Linton’s Gareth Wright (72) and former Mortonhall man David Patrick (71).
The event attracted the biggest field so far in the four PGA Optical Express Tour events this year and was hailed as a huge success.
“This is all about our, and the PGA’s, desire to see the next generation of Scotland’s elite golfers flourish and take their rightful place on the global golfing stage,” said David Moulsdale, chief executive of Optical Express Group.