Williams also handed out eight assists for the Nets, who were without Johnson for the third straight game due to a foot injury.
Brook Lopez helped pick up the slack with 20 points, seven rebounds and five assists for Brooklyn.
The Hornets, who lost for the fourth time in five games, got 20 points and eight rebounds from Greivis Vasquez.
Rookie Anthony Davis left the game with an apparent left shoulder injury in the third quarter after scoring just six points.
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