Having qualified second on the grid at Silverstone, Italian racer Bagnaia had taken the lead over pole-sitter Aleix Espargaro on the opening lap of Sunday’s race.
However, he soon found himself in the battle for third in the second part of the race after Martin overtook him with eight laps to go.
Martin, who had shown promising pace throughout the weekend, looked on course to victory, but made a costly mistake in the final moments, with Bastianini capitalising after qualifying third.
Australian racer Jack Miller (KTM) finished in 12th place to sit 16th in the championship table, while compatriot Remy Gardiner crossed in 18th place on his Yamaha.
Six-time MotoGP champion Marc Marquez had started seventh but rode his Gresini Racing bike with purpose to finish fourth.
Martin now leads the championship by three points, with reigning champion Bagnaia dropping to second and Bastianini maintaining his hold on third. Marquez sits fourth in the table.
“It has been a very difficult race because I made some mistakes in the start and was in fourth place, but after I was confident ...,” said Bastianini, who also won the sprint on Saturday.
“I closed the gap to Aleix and to Pecco [Bagnaia]. The last four-five laps Jorge pushed a lot, and it was too difficult to close the gap to him.”
AAP
