Avery Bradley (20/3/4) hit a game-winning three-pointer with 0.1 seconds remaining to lead the Celtics to an improbable comeback, as Cleveland led 66-50 at halftime.
Marcus Smart (27/5/7) entered the starting lineup in place of the injured Isaiah Thomas and delivered the best playoff performance of his career, going 8-for-14 from the field and 7-of-10 from three.
While Kyrie Irving (29/2/7) and Kevin Love (28/10/3) were very efficient, combining to shoot 18-for-31 overall and 11-of-19 from three-point range, LeBron James (11/6/6) surprisingly struggled, going just 4-for-13 with no fourth-quarter points.
Boston had 28 assists to just nine turnovers in the impressive team win on the road.
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