The World No 31 fired a stunning eight-under-par course record of 64 at Dundonald Links to put the pressure on Shinkwin, who just needed a par at the par-five 18th hole to win the tournament outright.
But the Englishman took four shots from the edge of the green to drop into a tie with Cabrera-Bello on 13-under-par overall.
And the Ryder Cup player hit a fantastic shot into the final green when the two returned in the playoff to set up a tap-in birdie, and secure the third Tour title of his career.
Shinkwin had to settle for second and a place in next week’s British Open at Royal Birkdale, while Frenchman Matthieu Pavon also grabbed a spot with a final-round 66 that saw him finish three strokes adrift of the leading duo.
Australian Andrew Dodt holed a birdie putt on the final hole to take the third and final Open invitation on offer, which will be his first major championship.
Branden Grace was the leading South African in joint 15th position on six-under, seven shots off the pace.
Also read: Kevin Anderson wins New York Open