Detroit IndyCar: Sebastien Bourdais wins ahead of Conor Daly

Championship leader Simon Pagenaud and Penske Dallara-Chevrolet team-mate Helio Castroneves stormed away from the rest of the field from their front row starting positions, but an early impact by ex-Formula 1 driver Max Chilton into the wall on the back straight meant they went off strategy.

With the rest of the field having already pitted before lap 10 of 70, the pair opted to eke out their first stint to switch to a two-stop strategy.

On the restart it was Will Power who tiptoed into race-winning contention, passing Juan Pablo Montoya and Carlos Munoz to move into third position.

After Pagenaud and Castroneves pitted on laps 23 and 24 it was Power and Montoya who were leading, but Pagenaud found his way back into the lead after the second stops, taking advantage of a pit-exiting Montoya's tussle with Power.

Under those stops Bourdais had quietly put himself into the top four places by running an aggressive fuel strategy compared to the fuel-saving Penske men.

KVSH Racing driver Bourdais maintained fourth after the second yellow flag, which was caused by a loose wheel from Power's Dallara-Chevy at the Turn 7 right-hander at the end of the back stretch.

On the final stops with just 10 laps remaining a lightning fuel-only stop for Bourdais from the lead put him out in second, crucially ahead of Castroneves and Pagenaud, and behind only Conor Daly who had one stop to make.

Daly opted for a similar strategy to take second ahead of Montoya, leaving four-time CART champion Bourdais to claim the win.

Castroneves and Pagenaud couldn't hold on in their fuel-saving strategy, and were forced to pit, leaving them finishing fifth and 13th respectively.

RESULTS - 70 LAPS: