Johnson went on to his second consecutive victory, and took a seven-point lead over Keselowski into Sunday's race at Phoenix, the penultimate event in the 10-race Chase for the Sprint Cup championship.
So why didn't Keselowski go for broke?
"Jimmie has never done anything to me to deserve to be raced in that manner," he said. "When I race people the way I race them, I race them off of a code that you know usually exists off how they've started racing me. He never did anything to deserve to be wrecked, that's for sure. I'm not in the habit of just wrecking people just to wreck 'em. Now obviously if somebody does something to push me around, that's a little different."
His record speaks for itself, and Phoenix was the site of Keselowski's first meeting with NASCAR chairman Brian France during his 2009 feud with Denny Hamlin.
Keselowski had staked a reputation as an aggressive driver who was unapologetic for anything he had to do on the track to be successful. He would not back down to anyone, and he had no interest in hearing any sort of lectures about etiquette or respect for veterans.
Now, three years later, he's in the thick of a championship race and Hamlin himself sees a changed driver.
"He's better. He'll tell you he's better now and, obviously, it's leading to a lot of success," Hamlin said. "I think that Brad is one of the best racers out there at this point. Not only from the speed that he has, but the ethics in which he races. He's a great guy to race with. Really to me, there's no resemblance from the Brad before to the Brad now."
So much so that Johnson never worried Keselowski would race him dirty on the final two restarts at Texas.
"I really feel like he was extremely aggressive and had that mindset of going for broke," Johnson said. "But we all evolve as drivers and I think he was more in control of his vehicle Sunday night than he was when he was new to the sport."
Nationwide Series • Joey Logano picked up his ninth series win of the season, and a wreck by Elliott Sadler helped co-leader Ricky Stenhouse Jr. move a big step closer toward a second championship.
Sprint Cup Series
P AdvoCare 500
TV • ESPN