Charlotte defeated the Nets for the first time in eight tries, having last won against them on April 11, 2011.
Walker hit four 3-pointers and his two free throws with six seconds remaining lifted the Bobcats in front by four. Charlotte ended a two-game skid and climbed back to the .500 mark.
Brooklyn was playing without center Brook Lopez for a third straight game. Lopez is recovering from an ankle injury. In addition, Brooklyn's Deron Williams twisted an ankle in the second quarter and did not return.
The Nets have lost six of their last seven.