Durant, the NBA's leading scorer, limped off the court during the third period of Oklahoma City's win over Indiana on Wednesday and his appearance Friday was in doubt until game time.
He ended any concerns about his condition, however, by playing 40 minutes while claiming eight rebounds and adding five assists.
Russell Westbrook had 28 points and nine assists for the Thunder and his 3-pointer with 1:03 touched off a game-ending, 9-4 run after Atlanta had cut its deficit to two.
Joe Johnson scored 24 points for the Hawks, who have dropped five of their last eight.
Oklahoma City has won each of the last four meetings with the Hawks.