The Bobcats have won back-to-back games for the first time this season.
Washington held a one-point lead midway through the fourth quarter before Charlotte closed the contest on a 15-6 run.
Wallace added 14 rebounds while Boris Diaw had 19 points and D.J. Augustin 17. The win came after the Bobcats had edged Toronto by five points Wednesday. All three Charlotte victories this season have come on the road.
Andray Blatche led Washington with 22 points and nine rebounds. Rookie John Wall had 13 points and only one turnover.