Ariza also grabbed 10 rebounds while Nene supplied 19 points and eight boards as the Wizards won for only the second time in six games.
John Wall also played a big role in the triumph with 13 points and six assists.
The Wizards used a 22-5 run late in the first half to put the contest away.
The Bobcats got 29 points and six assists from Kemba Walker in tumbling to their 10th consecutive setback.
Gerald Henderson added 17 points for Charlotte.