Two years ago, Brad Keselowski revved up NASCAR's Chase by using his bumper to rough up championship contenders Matt Kenseth and Jeff Gordon.
His aggression sparked a wild postrace fight with Kenseth at Charlotte Motor Speedway and an all-out brawl with Gordon's crew at Texas.
The incidents fired up fans and sent a charge through the 10-race Chase, one that generated momentum going into the season finale and the championship race.
Last year, it was Kenseth and Joey Logano getting into it. Logano wrecked Kenseth to win at Kansas. Kenseth retaliated at Martinsville and got suspended two races.