IndyCar never threw the flag and Sato led Dixon across the finish line under yellow. Dixon, who led 111 of the 200 laps in pursuit of his own second Indy win, was visibly disappointed.
"Definitely a hard one to swallow for sure. We had such a great day," Dixon said. "First time I've seen them let it run out like that. I thought they'd throw a red."
Unlike NASCAR, which typically sets up two-lap shootouts to the finish when a caution interrupts the ending, IndyCar rarely follows the same procedure. The series did throw a late red in the 2014 Indy 500 and it infuriated purists.
This time, with just four laps remaining after Pigot crashed, there really wasn't enough time to allow for a proper shootout. Dixon had figured he would ultimately run down Sato as Sato worked through lapped traffic, and he believed Sato's team was cutting it close on fuel.
None of it mattered in the end as Sato was able to coast around the speedway then ride the lift new track owner Roger Penske installed to take the winner to an elevated victory circle. Along for the ride were team owners Bobby Rahal, the 1986 Indy 500 winner, and David Letterman, his mask buried in an unruly gray beard as he greeted Sato.
Sato became the first Japanese winner of the Indy 500 in 2017. Graham Rahal, Sato's teammate at Rahal Letterman Lanigan Racing, was third behind Dixon.
Sato knew Dixon was going to be tough to beat under green.
"I know Scott was coming right through, out of turn four, he was screaming coming," Sato said. "I had to hold him off."
The celebration was somewhat muted as the RLL team had a socially distanced winner's circle. Penske was forced to host his first 500 as owner of the iconic speedway without fans and it made the largest venue in the world eerily quiet. The speedway typically draws more than 300,000 spectators on race day; Penske said there would be only 2,500 in attendance Sunday.
It was Pigot, the third Rahal driver, whose crash set up the controversial finish. His vicious hit destroyed his car and he was prone on the track being treated before he was taken to a local hospital for further examination. IndyCar said he was awake and alert.
The Sato win helped Honda snap Chevrolet's two-year Indy 500 winning streak. Santino Ferrucui finished fourth as Honda took the fist four spots.
Reigning series champion Josef Newgarden was fifth, the highest-finishing Chevrolet driver and best of the four-car Team Penske group. Chevrolet lagged behind Honda in speed the entire buildup to the 500 and had just one driver start in the front nine.
Mired in traffic, the Chevy group never contended.
No one did, really, as Dixon seemed to have it under control after casually passing pole-sitter Marco Andretti in the first turn of the first lap and pulling away. Andretti was seeking to end the 51-year losing streak for his famous family and had a shot with the first Andretti pole in 33 years. After Dixon took command, Andretti slid back into the field and ultimately finished 13th.
Fernando Alonso, attempting to win the final leg of motorsports' version of the Triple Crown, was 21st and never contended. This was his third attempt at winning Indy and the two-time Formula One champion is returning to that series in 2021.
With AP
