LOS ANGELES — Alexander Rossi roared to victory at the IndyCar series race at Road America on Sunday, describing his dominant performance as "the best race" of his career.

The 27-year-old American had finished second in three of his last four races but he wasted no time establishing his intent, passing pole sitter Colton Herta on the very first lap.

"It's probably the best race I have ever driven," Rossi said. Rossi won by more than 28 seconds over runner-up Will Power to finally break through and claim his second victory as the IndyCar season heads into its second half.

"You don't complain too much about finishing second because it is still a good result," he said. "The motivation this week was higher than ever and we were able to execute."

Former Road America winner Power was second while defending champion Josef Newgarden edged Graham Rahal for third and Scott Dixon rounded out the top five.

Rossi needed only a few seconds to seize control of the race with an audacious move on the opening lap, leaving Herta scrambling to catch up on the 14-turn, 4.014 mile track.

This was Rossi's second win of the season to go with a similar dominant ride two months ago on the Long Beach, California street circuit. He then finished second in three of his next five races including a runner up at the Indianapolis 500.

The win also moved Rossi to within just seven points of series leader Newgarden as he gears up for a second half run at the championship title. Newgarden now has 402 points and Rossi is at 395.

"This was a win we needed," said Rossi who led for all but one lap. "Penske was getting the upper hand and so winning the way we did stated our intentions."

Five time series champion Dixon also had an impressive day of racing. He rebounded from an opening lap spinout to catch the field. He then weaved his way through the pack, passing three cars on the final lap to place fifth.

Herta, who at 19 became the youngest IndyCar pole sitter in history on Saturday, finished eighth on a set of worn out tires. — AFP