Helio Castroneves, who pitted on Lap 147 of 200 on the 1.5-mile Kentucky Speedway, inherited the lead when the leaders had to take a splash of ethanol in the final stages of the Kentucky Indy 300 and went on to win his second race of the season.
Pole sitter Ed Carpenter finished second at the track for the second year in a row and Panther/Vision Racing teammate Dan Wheldon was third. Tony Kanaan charged from 26th in the 27-car field to fourth and Dario Franchitti was fifth.
Franchitti closed the IZOD IndyCar Series championship points gap on Will Power, who finished eighth, to 17 with two races left.
Also on Sept. 4, Pippa Mann did everything right to win her first Firestone Indy Lights race. J.K. Vernay did just about everything right during the season - and just enough in the Drive Smart. Buckle Up Kentucky 100 - to virtually wrap up the series championship.
Mann, the pole sitter in the No. 11 Sam Schmidt Motorsports car, jumped to a large lead after a Lap 5 restart and cruised to a 6.8372-second victory over James Hinchcliffe's No. 2 TMR-Xtreme Coil Drilling entry. She's the second female (Ana Beatriz at Nashville and Iowa) to win in Firestone Indy Lights.
Vernay, who was third in the No. 7 Lucas Oil/CJ/Sam Schmidt Motorsports car, takes a 48-point lead over Hinchcliffe into the season finale Oct. 2 at Homestead-Miami Speedway and only needs to take the green flag to clinch the title.