Spain's Alex Palou captured his third consecutive IndyCar season title and fourth in five campaigns by finishing third in Sunday's Portland Grand Prix, which was won by Australian Will Power.

Palou became only the fourth driver in IndyCar history to win three consecutive season crowns after American Ted Horn, France's Sebastien Bourdais and Scotland's Dario Franchitti.

"It's unbelievable," Palou said. "It's crazy. I couldn't be happier right now. This has been an amazing season, an amazing five years with CGR (Chip Ganassi Racing).