OKC used an array of lineup combinations to post its fifth straight victory over Denver since April 5.
With 1:08 still left in the first quarter, the Thunder's three most bulky big men — Kendrick Perkins, Nick Collison and Nazr Mohammed — had collected two fouls each.
Adding to the dilemma, the Thunder's two other centers — Byron Mullens and rookie Cole Aldrich — were both inactive and not part of the team's 12-man roster.
Kevin Durant, who spent much of the night playing the stretch-4 position, shot just 7 for 22 from the field, but still managed to score a game-high 26 points.
Fellow All-Star Russell Westbrook added 23 points, nine rebounds and eight assists. But Ibaka had the biggest presence under what could have been dire circumstances.
Despite being short-handed, the foul-plagued Thunder still managed to outrebound the Nuggets 49-43 and had a 13-12 advantage in second-half points. Denver outscored OKC 32-30 in the paint.