The Gresini Ducati rider lined up third and despite briefly falling back off the line to fifth, took two positions in as many corners to run second.
He snatched the lead from KTM rider Jack Miller at Stowe the following lap and despite VR46 rider Bezzecchi’s late charge, Marquez took his maiden win.
Bezzecchi’s second place finish sees him take second in the standings, with Maverick Vinales finishing third for Aprilia for his first sprint podium.
With Bezzecchi lining up on pole, he was embroiled in a battle for the lead with Miller, the Australian taking the lead into Brooklands on the first lap.
GasGas rookie Augusto Fernandez slotted into third before he was passed by Pramac Ducati rider Jorge Martin, with Marquez then passing him for fourth.
Martin briefly led at the end of the first lap before Miller retook the lead on the Hamilton Straight, with Martin second and Bezzecchi in third.
Behind, both Aprilias had a good start, with Vinales up into fifth by lap two while team-mate Aleix Espargaro slotted in behind him.
Marquez passed Martin at Copse before getting past Bezzecchi at Maggotts and Becketts for second.
As Miller ran wide, the Spaniard pounced, taking the lead at Stowe as Bezzecchi followed him through into second at Vale, with Miller falling to third.
Vinales soon passed Martin before charging after Miller, eventually making it into the podium places at the start of lap six.
Source: Autosport