Ibaka missed not one but two dunks in the first half, Thabo Sefolosha had an airball and the Grizzlies, who had been so good at limiting turnovers, had five in the first quarter alone.
Sefolosha had a two-handed slam on a fast break and also assisted on Kendrick Perkins' two-handed dunk during the burst, which extended Oklahoma City's lead to 60-45 before Harden's driving layup in the final second before halftime.
The Thunder were already up by 23 when Larry Hill connected on the half-court shot and went bounding toward Oklahoma City's huddle in celebration, getting congratulated by Thabo Sefolosha before the team's bison mascot pulled him back away.