Stewart shook off the weeklong rumors that he wants a release from his Sprint Cup contract with Joe Gibbs Racing, and also withstood a late challenge from Dale Earnhardt Jr. to win on the Nationwide circuit for the first time in two seasons.
He had enough horsepower to fight off Earnhardt down the stretch to win for the first time ever in 24 races on any circuit at Talladega.
Stewart had finished second six times without a victory in Sprint Cup races.
The race featured a 14-car crash on lap 71 and former Indy 500 winner Dario Franchitti suffered an ankle injury in a separate crash on the 10th lap.
Stewart drove his No. 20 JGR Toyota to his second pole position on the circuit this season and the sixth of his Nationwide career.