DETROIT — Rookie Justin Wilson raced to his first IndyCar Series victory today, edging Helio Castroneves in the Detroit Indy Grand Prix.

Castroneves led for the majority of the road race on the Belle Isle course, but was penalized for blocking Wilson and was forced by rule to relinquish the lead with fewer than 20 laps to go.

Series points leader Scott Dixon finished fifth. That result, coupled with Castroneves' strong showing, means the IndyCar championship will be decided at next weekend's final points race at the Chicagoland track.

The odds of winning the series title still favor Dixon, who entered the Detroit race 43 points ahead of Castroneves.