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HOMESTEAD, Fla. -- NASCAR Sprint Cup Series driver Kyle Busch capped a most improbable comeback Sunday night at Homestead-Miami Speedway, capturing the 2015 NASCAR Sprint Cup Series championship while winning the Ford EcoBoost 400.
Busch, 30, passed race leader Brad Keselowski on a final restart with seven laps remaining, then pulled away from fellow Chase for the Sprint Cup contender Kevin Harvick to score his fifth win of the season and secure his first premier series title.
It was also the first Sprint Cup Series championship for automaker Toyota, which entered the series in 2007.
"A dream of a lifetime, a dream come true," Busch said. "I just can't believe with everything that happened this year and all the turmoil, all the things that I went through, that my wife (Samantha) went through and the people that are around me went through. This championship is all for these guys, my wife, my family, everyone who has had to sacrifice so much to get me here to this place today, whether it was on my team right now, or on my teams in the past."
"Adam Stevens (crew chief) prepared such a great race car. Adam Stevens is my hero. I love that guy."
Busch (Joe Gibbs Racing), Harvick (Stewart-Haas Racing), Jeff Gordon (Hendrick Motorsports) and Martin Truex Jr. (Furniture Row Racing) advanced through this year's 16-team, 10-race Chase format to qualify for a shot at the title.
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Busch said he never doubted that he and his team could orchestrate such a stunning comeback.
"Oh yeah, no doubt," he said. "The rehab ... getting ready and focused, all that was the hardest part and the hardest thing I have ever gone through. To put it all together and be here tonight, this wasn't that hard."
Sidelined for the season's first 11 points races after suffering a broken right leg and fractures to his left foot in an XFINITY Series crash at Daytona International Speedway, Busch returned to win five times. Sunday's victory was the 34th of his career.
Busch can thank debris on the race track for the race win. It was driver and team that won the championship, however.
Seemingly on his way to a second-place finish that would have still secured the title, Busch shot past Keselowski (Team Penske) on a Lap 261 restart for the 18th and final lead change of the night.
"I knew it was time to go," Busch said. "I don't know why Brad chose the bottom, but he gave me the top and I thought, 'This is interesting.'"
The restart order put Harvick directly behind Busch, who said, "I knew I just had to protect whatever Harvick tried to do if he was going to shoot the middle or shoot the gap or whatever it was going to be."
"I don't know if Brad spun his tires or what. We got to Turns 1 and 2 and we were pretty even; I just looked into (Turn) 4 and gave it everything I had those last seven or eight laps."
Officially, it was Busch, Harvick and Keselowski finishing first through third, with Joey Logano and Kyle Larson rounding out the top five.
"I don't really know if there was a right one or wrong one, to be honest," Keselowski, who led a race-high 86 laps, said of the lane choice call. "We just weren't fast enough and I don't think it would have mattered either way."
Gordon ended his illustrious driving career with a sixth-place finish while Truex wound up 12th.
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"His talent is so strong, and that team really found some things this year," Gordon, a four-time champion making his final start, said of Busch, adding that he's seen "a changed Kyle."
"When he came back, not only was he driven and just inspired by it, but you can tell he was racing smarter, with more patience, just being more deliberate. ... I think he showed it right away when he came back that there was a pretty good chance he was destined to win this championship."
It wasn't a down-to-the wire battle for the championship or for the race until the final caution. With 67 laps remaining, Keselowski was easily out front while Busch enjoyed a lead of more than one second over Harvick for second place. Gordon, who had led earlier, ran ninth and Truex was just outside the top 10, running 12th.
A fire on pit road and an ill-handling car stymied the efforts of Truex and his team for the first half of the race; a two-tire gamble during pit stop on Lap 168 put him out front.
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But the lead was short-lived; Truex soon found himself free-falling through the field, eventually settling in just outside the top 10.
Gordon made his way to the front for the first time following a Lap 36 restart, shooting past the soon-to-be champ for the lead and bringing the crowd in the grandstands to their feet.
Harvick took charge moments later with a power move on a Lap 45 restart. A multi-car accident involving Dale Earnhardt Jr., Clint Bowyer and others erupted almost as soon as Harvick took control, bringing the yellow flag for the fourth time.
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The defending series champion was able to build as much as a 1.5-second lead over Busch and led 46 laps before a cycle of green-flag pit stops allowed Joey Logano to move to the top spot.
Afterward, Harvick could only smile as he watched Busch celebrate on stage.
"He broke his leg at Daytona, and to come back from everything that he came back from ... that's a great comeback story from where he was after Daytona," said Harvick.
The race began 1 hour, 35 minutes late due to rain but ran uninterrupted by weather conditions following its 4:50 p.m. ET start.