The Nets have captured three out of four and have won back-to-back games for the first time this season, both on the road. They defeated Philadelphia Wednesday, with Williams scoring 34 points.
New Jersey took an 11-point lead into the fourth quarter and held on in part due to a big night from 3-point range. The Nets hit 10 from beyond the arc and Williams was 5-of-9.
New Jersey overcame the most productive night as a professional to date for Cleveland rookie Kyrie Irving.
Irving made 10-of-20 shots from the field and scored 31 points, the last of them coming on a 3-pointer at the buzzer that brought the Cavaliers as close to the Nets as they had been since late in the first half. Irving's previous career high had been 26 points scored against Phoenix Jan. 12.
Cleveland lost for the fourth time in five games.