Australian driver Will Power has won the IndyCar Grand Prix for his maiden triumph of the season, leading 61 of 85 laps on Indianapolis Motor Speedway's road course.

Power's victory was the 30th of his career and his second in Indianapolis, as he won the inaugural event in 2015.

He held off New Zealand's Scott Dixon and American Ryan Hunter-Reay, who claimed second and third place respectively.

The Toowoomba-born Power, who won the 2014 IndyCar series title, was virtually untouchable all weekend. After winning pole in a track-record time, he only surrendered the lead twice on Sunday (AEST), both after pit stops.

"I was just very conscious of the gap Dixon was closing and I kept thinking, 'He's going to burn his tires off'. Then he kept closing," Power said.

"Then boom, suddenly they went and I knew we were good."

Power, 36, is fifth on the IndyCar series overall standings with 145 points, 46 adrift of Penske team-mate Simon Pagenaud.

"It was good to get a win," Power said. "It was good for everyone."

AAP/ABC