Jerryd Bayless made a three-pointer with three seconds remaining in regulation to send the game into the extra frame, where the Grizzlies finished off the defending Western Conference champions at home.
Mike Conley led the way for the Memphis (46-21) with 24 points on 9-of-21 shooting from the field and added seven assists and five rebounds. Gasol, who played hero, collected a double-double with 14 points and 15 rebounds. Memphis didn't shoot well as a team at just a 36 percent clip, but overcame it by outrebounding the Thunder by a margin of 54-46.
Kevin Durant had a game-high with 32 points and grabbed eight rebounds to lead the Thunder (50-19). Russell Wetbrook added 20 points, four rebounds and three assists with four steals on the defensive end as the OKC couldn't overcome the Grizzlies' stout defense that held them to just 35.7 percent from the field.
The back-and-fourth, defensive battle between the two conference powerhouses featured 14 lead changes and four ties.
An encore for the game-winner: