The top pick in the draft had 13 points during an 18-0 run in the third quarter. He capped the run with a steal and a transition dunk that put Washington up 62-60 with 2:05 left in the period.
The former Kentucky sensation made 10 of 23 shots and had the highest total by anyone in the summer so far.
The Wizards won the game on Lester Hudson's jumper at the buzzer. The Hornets took an 89-88 lead on Quincy Pondexter's three-point basket with 2 seconds left in the game.
Maurice Ager led the Hornets with 23 points.
JaVale McGee had 29 points for the Wizards.