Pramac Ducati rider Martin followed up his sprint win on Saturday with another virtuoso display to grab his second grand prix victory in three rounds, and his third of the season, albeit with just 12 of the scheduled 24 laps being completed.
With full points being awarded, Martin moves to within three points of championship leader Bagnaia with six weekends remaining.
Marc Marquez meanwhile was third, picking up a first podium finish in almost a year at Honda’s home race, while Marco Bezzecchi was fourth on the VR46 Ducati.
Although some spots of rain fell before the start, the entire field selected slick tyres for the warm-up lap, only for the heavens to open shortly after the race itself began.
KTM rider Jack Miller passed poleman Martin to lead a group of 16 riders that pitted at the end of the opening lap to change to their wet bikes, with the remaining five, led by Ducati tester Michele Pirro, bravely staying out on slicks.
It was Martin who led the wet-shod group after the stops, but he conceded the net lead to Aprilia’s Aleix Espargaro on the third lap when he ran wide at Turn 3.
Espargaro then took the lead proper when Pirro pitted at the end of lap four - the other slick-shod riders having by now changed to wets or been swallowed up by the pack in the worsening conditions - with Marquez his nearest pursuer.
But Martin was soon on the charge, passing Bezzecchi and then Marquez on the fifth lap to get back into third, with Bagnaia having taken second away from Marquez.
On lap six, Martin swept ahead of Bagnaia at Turn 9 for second, and two corners later he outbraked Espargaro to grab the lead.
Source: Autosport