Johnnie Parsons won the Indianapolis 500 when it first counted toward the Formula One championship in 1950.
The 1950 race was the third round of the newly created World Drivers' Championship. Unlike the European championship races, it was run under American AAA regulations with Indy roadsters rather than contemporary European Grand Prix machinery. Parsons drove a Kurtis Kraft-Offenhauser and led 115 of the 138 completed laps.
The race was scheduled for 200 laps, but heavy rain stopped it after 345 miles. Parsons was declared the winner ahead of Bill Holland and Mauri Rose. His victory earned nine championship points and made him the first American winner of a World Championship race.
A common mix-up is assuming that the Indianapolis 500 was a conventional Formula One Grand Prix. It counted toward the championship from 1950 through 1960, but its separate rules, cars and entry pool made it very different from the European rounds. The 1950 result is also sometimes remembered for the race's shortened, rain-affected distance.