Valtteri Bottas sealed the GP3 title by winning the first race at Monza after a head-to-head fight with title rival James Calado in the closing laps.
The ART Grand Prix pair fought their way to the front over the course of the race, and then had an exclusive battle for the win for the final three laps following a safety car period. Calado needed to beat the Finn to keep his title hopes alive, but he could not find a way through to delay Bottas's title celebrations.
Bottas had jumped from fifth to third at the start, but he spent the opening six laps of the race fighting with Manor's Rio Haryanto for that position. He finally broke free and took second from polesitter and early race leader Adrian Quaife-Hobbs on lap seven, and took the lead for the first time two laps later by deposing Nico Muller (Jenzer).
Muller fought back a couple of times but could never hold the lead, and he then lost second to Calado just before the safety car came out when Quaife-Hobbs crashed his Manor car at Ascari.
It took Calado two laps to launch an attack, meaning that Bottas only had to start defending on the final lap. He blocked the Briton into the first chicane, and then sealed the race by running his rival wide at the second chicane. That left Calado with too much ground to make up, so he had to settle for second place.
There was more action behind, as Haryanto and Muller swapped places five times in the final three laps with the Indonesian grabbing the final podium place.
Behind them, Simon Trummer put in an impressive drive to take fifth for MW Arden, with Conor Daly (Carlin), Antonio Felix da Costa (Status) and Mitch Evans (MW Arden) completing the points.