The rich got richer.
Matt Kenseth, the top seed in the Chase for the NASCAR Sprint Cup, added to his advantage in Sunday's rain-interrupted GEICO 400 at Chicagoland Speedway.
With a strong push from Kevin Harvick after a restart with on Lap 245 of 267, Kenseth pulled away to beat Joe Gibbs Racing teammate Kyle Busch to the checkered flag and deny Busch the second three-series weekend sweep of his career.
The victory was Kenseth's sixth of the season, tops in the Cup series. The driver of the No. 20 Joe Gibbs Racing Toyota claimed his first win at Chicagoland and the 30th of his career.
Harvick came home third, followed by Kurt Busch. Hendrick Motorsports teammates Jimmie Johnson and Jeff Gordon both overcame considerable adversity to finish fifth and sixth, respectively, as Chase drivers claimed the top six spots in the finishing order and 10 of the first 12.
Other championship contenders weren't so lucky. Pole winner Joey Logano brought his car to pit road under caution with engine issues on Lap 149 of 267. After Lap 175, the engine gave up the ghost, and Logano retired in 37th place.
With the nose of his car punctured during a pit road accident on Lap 169, Dale Earnhardt Jr. suffered an engine failure on Lap 226, his heavily taped car overheating and ultimately erupting in a geyser of steam and smoke. Earnhardt dropped out in 35th place.
The race was red-flagged for more than five hours as rain pelted the 1.5-mile track. The action resumed at approximately 10 p.m. ET with Kenseth in the lead.