SONOMA, Calif. -- What began as a tumultuous start to race day at Sonoma Raceway ended with Takuma Sato recording a season-best fourth-place finish in the GoPro Grand Prix of Sonoma.

Sato advanced a field-high 16 positions relative to his starting spot in the 85-lap race on the 2.385-mile, 12-turn road course.

Click it: GoPro Grand Prix of Sonoma box score

“It was a great effort by the whole ABC Supply team,” said Sato, driving the No. 14 A.J. Foyt Racing entry. “The guys did a tremendous job to change (the engine) in such a short time and give me a competitive car. Unfortunately, we caught debris in the first (Lap 1) accident and we had to change the nose and tires. We stayed on the lead lap and kept topping off fuel to make a slightly different sequence of pit stops from everyone else.

“(Race strategist) Larry (Foyt) and the engineers made good calls on strategy and it worked out really well. The crew did a great job on the stops. Unfortunately, on the last stop, we were leaving when Marco (Andretti) was coming in (pitted in box ahead) and I had to stop to avoid hitting him. Nevertheless, I overtook a few cars on the track, our strategy worked and the Honda engine did a great job in the end. Everyone is very happy.”

That includes A.J. Foyt.

Simon Pagenaud gained 12 positions in earning his third top-three finish of the season in the No. 77 Schmidt Peterson Hamilton Motorsports car, which kept him in contention for the Verizon IndyCar Series championship.

"Sonoma is a hard track to pass on, so we really made the race in the pits," he said. "The pit stops were awesome, and that's what made us jump so many positions. Our fuel strategy was very frustrating though, very tough for me. I had to save so much fuel, but in the end we made it to third, which is fantastic."

Juan Pablo Montoya picked up 14 positions to finish fifth – his seventh top five in the No. 2 Verizon Team Penske car. All the top-five finishers but race winner Scott Dixon qualified 10th or lower.