Yates, 23, was suspended after an administrative error led to him using an asthma inhaler without permission.
"I am going to enjoy this moment," the Orica-BikeExchange rider said. "It's my first victory as a full professional."
Yates' twin brother, Adam, was crowned the best young rider at the Tour de France, which finished on Sunday.
Simon Yates was sanctioned by governing body the UCI in June for a "non-intentional" anti-doping rule violation, resulting in the suspension.
He returned to action on 11 July and subsequently finished 20th at the Tour of Poland.
Simon Yates claimed his first victory since returning from a four-month drugs ban at the one-day Prueba Villafranca-Ordiziako Klasika in Spain.