A nightmare pitstop meant that Adrian Quaife-Hobbs had to wait to wrap up the Auto GP title, as Antonio Pizzonia won on his series debut at home in Race 1 at Curitiba.
Front-row starters Quaife-Hobbs and Chris van der Drift both made poor starts and got swamped by those behind. Pizzonia took the lead from third on the grid, ahead of Pal Varhaug (started fourth) and Sergey Sirotkin (started fifth).
Quaife-Hobbs got back ahead of Sirotkin and started pressuring Varhaug. Finishing third with Varhaug second would have been enough for Quaife-Hobbs to put himself out of reach.
However, an issue with the rear-right wheelnut saw him lose more than 15 seconds to Varhaug and drop him down the field.
Pizzonia opened up a five second lead over Varhaug in the first stint, but emerged from his stop less than a second ahead.
Sirotkin took the lead the race until making his stop late, rejoining just behind the Pizzonia-Varhaug battle.
Pizzonia held on to the lead, crossing the line 1.142s ahead to record a victorious return to single-seaters, while Sirotkin completed the podium behind Varhaug.
Daniel De Jong dropped to ninth on the opening lap, but made his stop early and went on to finish fourth, setting the fastest lap of the race on lap 10. That ensured that he finished fourth ahead of his Manor MP Motorsport teammate and driver coach Chris van der Drift, who kept Quaife-Hobbs at bay to finish fifth.
Pizzonia's fellow Ombra Racing driver, Brazilian and debutant Rafael Suzuki was seventh, with Francesco Dracone and Michele la Rosa the final cars running at the finish.
Quaife-Hobbs still has 64 points in hand over Varhaug, and with 48 points available at the final round at Sonoma the Kent racer will seal the title in Sunday’s race if he can finish inside the top seven, regardless of where Varhaug finishes.