Australia's Will Power has finished third as Spain's Alex Palou continued his dominance of the IndyCar Series by capturing the Sonsio Grand Prix title at the Indianapolis Motor Speedway road course.

Ganassi Racing's Palou, who sat on the pole, flew across the finish line 5.48 seconds ahead of Pato O'Ward on Saturday to become the first IndyCar Series driver since Sebastien Bourdais in 2006 to win four of the season's first five races.

He also became the first driver to win the Grand Prix in Indianapolis three years in a row.

Power and Kiwis Scott McLaughlin and Scott Dixon rounded out the top five on the 2.44-mile course that winds its way through the interior of the fabled Indianapolis Motor Speedway oval.

"I cannot describe the amazing season we've had so far," Palou said. "I owe everything to the team, Chip Ganassi Racing, my teammates, everybody who is working behind the scenes to make me look so fast on track. It's amazing. It's unbelievable."

Palou enters the two-week prep for the Indianapolis 500 with an IndyCar Series-leading 248 points. That's 97 points ahead of second-place Kyle Kirkwood, who also drives a Honda. Palou has won St. Petersburg, Thermal and Barber in addition to Saturday's race. He was second at Long Beach.

While the 28-year-old Palou is on pace to win the points title for the fourth time in five years, his immediate goal is claiming his first Indy 500 on May 25.

"Hopefully, we get to stay here (at the victory podium) again in a couple of weeks for the biggest race of the year," Palou said.

The all-time series record for wins in one season in 10 by A.J. Foyt in 1964 and Al Unser in 1970. There are 12 races remaining this season.