Wheldon returned to AGR for the 2004 season. At Phoenix International Raceway, the season's second race, Wheldon won his first career pole position and finished third. He took his first series win at Twin Ring Motegi where he led an event-high 192 laps from pole position. Wheldon qualified second for the Indianapolis 500; he led 26 laps to finish the rain-shortened race in third. His second win of the season came at Richmond International Raceway after holding off Team Penske's Hélio Castroneves on the last lap. Wheldon took four top-ten finishes in four of the next six races, before he achieved his third series victory in Nazareth Speedway's final motor race to move into second in the drivers' championship. His title challenge to his teammate Tony Kanaan ended in the season's penultimate round at California Speedway (now Auto Club Speedway), but he secured second in the standings from Buddy Rice at the season-ending Texas Motor Speedway race with 533 points.