Maclean won the opening round of the competition at Castle Stuart last month to book his place in the tour's grand final at Dumbarnie Links St Andrews, in October.
Now he has added the third round for good measure, carding a seven-under-par 63 to win by two shots from professionals John Henry (Clydebank) and Scott Grant (Panmure).
With Maclean having already booked his place in the 12-strong field for the final, Henry took the available place thanks to a better inward half.
Maclean was understandably delighted with another win.
He said: “Chuffed to bits and delighted to shoot seven under round a tricky golf course.
“Played really nicely, hit some great wedge approach shots and had my putting boots on all day.”