Cousins grabbed 19 rebounds while Isaiah Thomas added 24 with 12 assists for the Kings, who were playing shorthanded after trading Greivis Vasquez, Chuck Hayes, Patrick Patterson and John Salmons to Toronto before the game.
The players they got in return -- Rudy Gay, Quincy Acy and Aaron Gray -- were inactive for the contest, leaving them with just 10 healthy players on the active roster.
The Mavericks had their three-game winning streak snapped despite 21 points from Monta Ellis.
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