With the scores tied at 111 with 35 seconds left, Adams was first to a missed three from Russell Westbrook, tipping the ball home to give the Thunder a two point lead.
It proved to be the last bucket of the game, with Rockets guard James Harden missing a three, followed by the two teams exchanging free throws after intentional fouls.
Westbrook missed two of his four free throws at the charity stripe, but the Thunder survived as Harden came up short on a 25-foot pull-up three to win the game.
Adams finished with four points, six rebounds and two assists, shooting 2/5 from the field in 26 minutes of action.
Westbrook led the Thunder with another triple double, recording 32 points, 13 rebounds and 11 assists. He recieved assistance from forward Taj Gibson, who scored 20 points on 10/13 shooting.
Harden finished with 44 points in the loss, shooting a perfect 18/18 from the free throw line.
The series continues in Oklahoma City on Monday morning.