In 2004 Kanaan returned with Andretti Green Racing to drive the No. 11 7-Eleven Dallara IR03-Ilmor-Honda Indy V8 HI4R. At the season-opening Toyota Indy 300 at Homestead-Miami Speedway, Kanaan started and finished eighth. At the second race of the season, the Copper World Indy 200 at Phoenix International Raceway, Kanaan started second and led for 191 of 200 laps to win. Kanaan also took the points lead. At the Indianapolis 500, Kanaan qualified in fifth-place. In the race, Kanaan led for 28 laps and was battling with teammate and friend Dan Wheldon and Buddy Rice. Kanaan was running second to Rice on lap 174 when the caution came out for rain. The race was then stopped permanently on lap 180 with Kanaan in third. Kanaan went on to win both the Bombardier 500 at Texas Motor Speedway and the Firestone Indy 200 at Nashville Superspeedway. Kanaan also qualified on the pole position at the Michigan Indy 400 at Michigan International Speedway and the Honda Indy 225 at Pikes Peak International Raceway. Kanaan clinched the championship with a 2nd-place finish at the Toyota Indy 400 at California Speedway. Kanaan completed all 3,305 laps during the season. Kanaan scored 618 points to win the championship.