Sebastien Bourdais triumphed on a chaotic afternoon in Detroit to win the second race of this weekend’s IndyCar double-header.

Changing conditions, wildly different strategies and a late proliferation of yellows all made for a busy race, but Bourdais succeeded through a relatively conventional strategy and a stroke of good luck.

His big break came during the final stop when he managed to get out ahead of previous race leader Juan Pablo Montoya, and cycled into the lead when a group of off-strategy cars ahead of him made their own stops a few laps later.

At that point it was touch-and-go as to whether the KV driver could make it to the end on fuel, but his cause was helped immensely by a string of yellow flags that allowed him to stretch his mileage. Just how close it had been became clear when his car stopped towards the end of his slowing-down lap.

“It’s incredible after yesterday’s debacle,” Bourdais said. “We got everything wrong yesterday, but got everything right today.”

Montoya was in the same boat with fuel, and it was the need to stretch himself to the finish that prompted him to be cautious on the final restart, which allowed both Takuma Sato and Graham Rahal to pass him. His tank ran dry on the final lap, and he rolled across the line in 10th.

Despite the mishap the Colombian managed to extend his points lead over Penske team-mate Will Power, who endured a difficult afternoon.

He was running just behind Montoya in second early on when moisture found its way into his steering wheel and caused a series of electronic glitches that kept dropping his car into neutral.

Later, he was tagged at Turn 2 and spun into the sister Penske of Helio Castroneves, putting both out and bringing out a red flag with just a few laps remaining.

With light fading, race control switched to a timed race, and the cars restarted with just five minutes left on the clock.

Sato held off Rahal for second in a battle that had raged for much of the second half of the race.

Rahal had been ahead of much of that time, but was instructed to relinquish his position to the Foyt car after a particularly robust block.

The Power/Castroneves tangle was not the only friendly fire incident of the day: Scott Dixon was eliminated when he was pitched into the wall by the sister Ganassi Dallara-Chevrolet of Charlie Kimball.

Elsewhere in the Ganassi camp it was a busy afternoon for Sage Karam, who was put to the rear of the field for spinning Jack Hawskworth.

A few laps later he hit the Brit again, this time earning himself a drive-through penalty.

RESULTS – 68 LAPS:

Dixon ejected by team mate Kimball, Bourdais wins in Detroit