Boston let an eight-point lead slip away during the final 2 minutes of the fourth period and Atlanta's Jeff Teague forced overtime by hitting a jumper with 32 seconds left in regulation.
With the score deadlocked at 102-102, Terry launched his key 3-pointer. After an Atlanta turnover, Terry converted a pair of free throws with 9.9 seconds to go that clinched the victory.
Boston overcame a big game from Atlanta's Josh Smith, who narrowly missed a triple-double with 32 points, nine assists and eight rebounds.
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