2006 Indy Japan 300

The 2006 Indy Japan 300 was an IndyCar Series motor race held on April 22, 2006, in Motegi, Japan, at Twin Ring Motegi. It was the third round of the 2006 IndyCar Series season, the ninth running of the event, and the only race of the season to be held in Japan. Marlboro Team Penske driver Hélio Castroneves won the 200-lap race. Dan Wheldon, driving for Target Chip Ganassi Racing, finished second, and Tony Kanaan finished third for Andretti Green Racing.

Castroneves was awarded the pole position after rainy conditions washed out the qualifying session. He maintained the lead for the first 24 laps before struggling to pass a slower car, handing the lead to Wheldon for five laps. After Tomáš Enge and Ed Carpenter crashed, the leaders entered pit road for fresh tires and fuel, and Castroneves emerged ahead of Wheldon, thus giving him the lead for the next 64 laps. Castroneves pitted again on lap 94, and the lead was swapped among four drivers in the next six laps before he regained the lead again on lap 101. Castroneves continued his pure dominance, leading another 46 consecutive laps before coming in for his final pit stop on lap 147. Scott Dixon, who led five laps and had the momentum to steal the victory, stalled his engine during his final pit stop. Castroneves was not challenged by any other driver and led the final 50 laps en route to his ninth IndyCar victory and his second consecutive win of the season.

Castroneves' win allowed him to extend his Drivers' Championship lead with 146 points, 42 more than Wheldon. Dixon's poor result gave him a total of 92 points, falling back to fourth in the standings while Sam Hornish Jr. improved his position to third with 94 points. Kanaan, who overcame an unscheduled pit stop with less than 80 laps to go, maintained the fifth position with 89 points.