Mike Dunleavy added 17 points off the bench and Ekpe Udoh had 11 points and seven rebounds for the Bucks (3-4), who overcame a 20-point third quarter deficit. Larry Sanders had eight points and 13 rebounds.
The Bucks outscored the Bobcats 28-11 in the fourth quarter.
Lamb outplayed former Kentucky Wildcats teammate Michael Kidd-Gilchrist, making six of seven shots. Kidd-Gilchrist had four points in 13 minutes.
In what has become an annual tradition for the Bobcats in their final preseason game -- except for last year when the NBA lockout forced a change of plans -- the Bobcats offered free tickets to middle school children from North and South Carolina as part of their Cool School Field Trip.
Dozens of school buses from across two states were lined up outside the arena before the game, played at 11 a.m. EDT.
The children screamed, cheered and danced throughout the game making for a lively environment.
"Man, those kids were great," Bobcats center Brandon Haywood said. "I've played in Charlotte before, but there was nothing like this. It was a great atmosphere."
Bobcats guard Kemba Walker didn't get a chance to play in the game last year before the NBA had locked out the players, shortening the preseason.
"It was a good time out there, a lot of fun," Walker said.
The Bucks host the Minnesota Timberwolves on Friday, while the Bobcats visit Dallas to close out the preseason.