Scott Dixon won his fifth IndyCar championship with a second-place finish at Sonoma Raceway on Sunday.
Ryan Hunter-Reay won the race from the pole.
Dixon needed only a steady race to hold off challenger Alexander Rossi in the championship fight. Rossi broke his front wing on the opening lap when he ran into teammate Marco Andretti and it effectively ended his chances.
Dixon from there didn't take any chances and coasted to the title. His five championships trail only the seven won by A.J. Foyt.