"I didn't know if we'd be able to do it, you know? The 48 car is king here, him or the 24," he said in Victory Lane, referring to Johnson and his Hendrick Motorsports teammate, Jeff Gordon, who also has eight Martinsville victories.
"I've been on this journey for a while and every time you come to Martinsville, you just kind of draw a line through it like there's no way I'll be able to challenge those Hendrick guys or be up in the top 10," Busch said.
When it was over, Busch brushed aside talk about his in-race comments about his feud with Keselowski, who claimed that Busch "just drove right through me and ruined my day" on pit road, causing Keselowski to lose 30 laps and retaliate.
"He tried to flatten all four of my tires," Busch said of his former teammate with Roger Penske Racing. "That's a no fly zone. ... He will get what he gets back when I decide to give it back."
The race featured an event-record 33 lead changes, and Johnson expected there would be one more, but on a slippery day on the smallest circuit in NASCAR's premier series, the cars at the end weren't conducive to typical short-track racing.
"Man, we were so on edge slipping and sliding," Johnson said about the final laps duel, during which there was very little of the beating and banging that usually typifies end-of-the-day racing at Martinsville. "I think the lack of security in our own car kept us from feeling more racy and putting a bumper to someone or really getting inside someone aggressively."
Dale Earnhardt Jr. was third, followed by Joey Logano and Marcos Ambrose.
Virginia native Denny Hamlin, a four-time winner at Martinsville stung by criticism when he missed last week's race in Fontana, Calif., because of an eye infection, promised Friday that he would win, and qualified second, but finished 19th.
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