Motorsport: Swedish driver Felix Rosenqvist involved in high-speed crash, as Kiwis Scott Dixon and Scott McLaughlin struggle in Detroit

Kiwis Scott Dixon and Scott McLaughlin have had disappointing finishes in the first race of the Detroit Grand Prix on Sunday that was marred by a high speed crash to Sweedish driver Felix Rosenqvist.

Dixon - who sits third in the championship standings - started from 11th on the grid and was caught out by pit strategy to only make up three places to finish eighth.

Compatriot McLaughlin didn't fare any better to finish a lowly 19th.

Rosenqvist was hospitalised after smashing into the wall and causing the race to be delayed by a red flag for an hour and 16 minutes at lap 25 when Rosenqvist's throttle may have stuck open in turn six, and he crashed hard into a tire barrier and a concrete barrier.

The Swedish driver was extracted from the car and the barriers were fixed before racing resumed.

Rosenqvist was taken to the infield care center and then a local hospital, but was conscious, alert and talking according to IndyCar officials.

Sweden's Marcus Ericsson came through for an unpredictable win in the opening race in Detroit, and earn his first career series victory thanks to a late-race caution, a rival's mishap and some canny driving at the Belle Isle race course.

When race leader Will Power's car failed to answer the bell on a late round of pit stops under a red flag, Ericsson assumed the lead and held on as Belgium's Rinus VeeKay and Mexico's Pato O'Ward rolled up to challenge over the final three laps. They finished second and third, respectively.

"For once, things fell my way," Ericsson says. "It feels really good. For Will, I feel really bad for him with the way it ended for him.

"He did a tremendous job today. But it was my day today, and it was about time."

A Formula One veteran, Ericsson is the seventh different winner in the first seven races this season - something that hasn't happened since 2017 and a rarity in more than a century in the series, with five previous occurrences. He joins Alex Palou, O'Ward and VeeKay as first-time winners this season.

Power, who had a dominant car most of the day, suffered an apparent Electronic Control Unit (ECU) failure on the late pit stop, and while it was replaced quickly, the dejected driver finished 20th, three laps down.