Varejao, who has played no more than 31 games in any of his last three NBA seasons, hit a jumper that gave Cleveland a 93-91 lead and ignite a six-point run for the Cavaliers.
Kyrie Irving hit four free throws down the stretch to boost the Cleveland cushion to six and Varejao clinched it by making two more with three seconds to play.
Both sides shot 40 percent and Cleveland helped its cause by winning the battle of the boards 48-37.
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