Will Power won the first of two races at the Detroit Grand Prix.
Power finished 0.3308 seconds ahead of Graham Rahal on the bumpy, 13-turn, 2.36 mile street circuit on Belle Isle.
Simon Pagenaud and Mike Conway each finished first in one of last year's races on Belle Isle and both lost their shot to win early Saturday.
Pagenaud damaged his front left suspension when he ran into the back of Power, leading to a yellow. Conway did not have any one around him when he appeared to understeer into a wall on Lap 15, putting the race under caution.
Both will get another shot to repeat at the Detroit Grand Prix on Sunday as part of IndyCar's first of three doubleheaders this season.