The seventh-seeded Grizzlies never trailed in the second half and owned a commanding 81-64 lead with 7:44 left in the fourth quarter but went ice cold down the stretch, going the next seven minutes without a point as the Thunder clawed back in it.
All five Thunder starters scored during the ensuing 17-0 run, which Russell Westbrook capped with a corner 3 to tie the game at 81-81 with just under a minute remaining. Allen finally broke the seal for Memphis with a baseline drive for a jam at the other end, and he stripped Westbrook and went in for a layup to make it 85-81 with 33.1 seconds left.
Then, it was deja vu for Memphis. Three nights after Kevin Durant's four-point play in the final seconds helped the Thunder force overtime, Westbrook did the same on Thursday with 26.6 ticks to play. The electric point guard rose up for a 3-pointer from the top of the key and drew contact from Allen, hitting the shot and ensuing free throw to tie the game at 85. Both teams came up empty on their last possessions in regulation.
Durant opened the extra session with a three-point play down low, but Conley followed a Marc Gasol post bucket with five straight points, and the Grizzlies never trailed the rest of the way.
Randolph posted team highs with 10 rebounds and six assists, Gasol netted 14 points with eight boards and for the second straight game Beno Udrih came up huge off the bench for the Grizzlies, posting 12 points in 14 minutes.
Game 4 is set for Saturday in Memphis.