Gallinari netted six key points down the stretch and JaVale McGee (15 points) provided a decisive tip-in with 46.7 seconds remaining as the Nuggets doused the Grizzlies' bid to set a new franchise consecutive wins record.
Kenneth Faried chipped in a double-double of 13 points and 13 rebounds as Denver ended its own three-game slide.
Zach Randolph helped out with 12 points and 13 rebounds in the loss.
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