And this one got tight, too, especially when Keselowski ran out of gas on pit road during green flag pit stops. It put him a lap down with Johnson leading, and Keselowski and crew chief Paul Wolfe frantically tried to figure out how dire the situation had become.
Wolfe crunched the numbers, figuring the No. 2 Dodge would cycle out in the mid-20s, a lap down from the leaders.
"I know the scenario, and it's not good," Keselowski said.
But minutes later, Johnson went to pit road for his own stop and pulled away with a missing lug nut. NASCAR flagged the Hendrick Motorsports team and Johnson was forced back to pit road for another stop.
The Penske team was unsure if Keselowski wanted to know what was going on with Johnson.
"I've got a big picture story if you want to hear it," a team member radioed, then informed Keselowski that Johnson had to pit again.
"Ten-four. Thank you for telling me. We're back in the game. I got it," he said.
It got worse for Johnson from there. He broke a rear end gear in his Chevrolet and went to the garage with 40 laps to go, essentially clinching the championship for Keselowski.
"It all unraveled pretty quick," Johnson conceded.
No longer needing to save fuel, and no longer needing to play it conservatively, Keselowski waived off Wolfe's playbook.
"If he's in the garage, let's race," he said.
That's been Keselowski's attitude since he burst onto the NASCAR scene. He first caught attention as a brash driver for Dale Earnhardt Jr.'s Nationwide Series team, and he was unapologetic for his aggressive driving and his refusal to back down in long-running feuds with established stars Denny Hamlin and Carl Edwards.
But he's been calmer and more focused since teaming with Penske in 2009. Still, his fame had been largely for the Daytona 500 tweeting.
NASCAR loved the attention it received, but quietly admonished him later for having a phone in his car, which is banned because it can manipulate electronic fuel injection systems. So when he tweeted again last week under red at Phoenix, NASCAR fined him $25,000 — which angered fans who felt a mixed message had been sent.
But Keselowski, who was tweeting into the early morning hours Sunday, handed his phone over with no resistance right before he climbed into the car at Homestead.
The win is the first for Dodge since Richard Petty's Cup title in 1975, and comes as the manufacturer is leaving NASCAR. Penske announced days after the Daytona 500 it will move to Ford next year, and it led to Dodge's decision to pull out of NASCAR.
"Not one failure all year long in that Dodge engine, so I want to thank Dodge for what they've done for us," Penske said after Keselowski secured the title.