Francesco Bagnaia returned to winning ways with a dominant Algarve Grand Prix victory as he closes on the end of his debut season with the Ducati factory team in top form.

Bagnaia was unable to take the MotoGP title race right down to the wire, with Fabio Quartararo clinching the championship last time out when his nearest rival retired.

But Bagnaia has undoubtedly been the form man on the grid from September onwards. Indeed, had he not crashed at the Emilia Romagna GP, the Italian would have had Quartararo firmly in his sights – the new champion went down at Turn 5 with five laps remaining on Sunday, his first error of the season.

Meanwhile, Bagnaia had continued his stunning run of poles with a fifth in succession at Portimao and, as in the first two races in that sequence, protected his position for a third win of the year.

That was enough to seal the constructors' championship for Ducati, who also moved into the lead in the teams' standings as Jack Miller joined Bagnaia on the steps.

The pair both started from the front row and Miller jumped ahead of the pole man into the first corner but then relinquished the lead.

Joan Mir caught Miller, too, while Bagnaia steadily disappeared into the distance, finishing well clear.

Mir held off Miller for his joint-best result of the year, while Alex Marquez also nipped ahead of the second Ducati man when his pace just relented slightly.

Marquez, pursuing a first podium of the year, could not keep Miller at bay, though, and a run of nine races without appearing on the steps ended for the Australian as the grand prix was prematurely brought to a close.

Home hopeful Miguel Oliveira was involved in a nasty crash with Iker Lecuona, prompting a red flag and the end of the race with more than three quarters completed. Both riders were quickly confirmed as conscious.