Helio Castroneves has tightened up the IndyCar Series points race by winning at Edmonton.

Castroneves had to hold off Takuma Sato over the final 15 laps of Sunday's race to pick up his second win of the season.

It pushed Castroneves up to second in the standings, and he trails leader Ryan Hunter-Reay by 23 points with four races remaining. Power finished third, but lost a spot to his Penske Racing teammate in the standings.

Still, Power cut his deficit in the standings from 35 points to 26 behind Hunter-Reay. Sato was second, Power third and Graham Rahal and Alex Tagliani rounded out the top five.

Hunter-Reay finished seventh.