Simon Pagenaud won the crash-filled Detroit Grand Prix on Sunday for his first IndyCar victory.
The Frenchman finished 5.6 seconds in front of James Jakes in the second of two races on the 2.36-mile Belle Isle street course.
The reigning IndyCar Rookie of the Year hadn't finished better than second.
Mike Conway, who won Saturday's race with just three cautions, finished third. Scott Dixon was fourth, followed by Dario Franchitti and Marco Andretti, who pulled into a tie with Helio Castroneves for the IndyCar points lead.
AJ Allmendinger was in a pack of cars when he hit a wall on the opening lap, triggering the first of six cautions that stunted about the first half of the race.