Mayo made a career-high seven 3-pointers, including one that put the Mavericks ahead for good late in the second quarter and another that capped a 24-8 run that made it 76-61 in the third.
Dallas improved to 16-0 all-time against Charlotte.
Chris Kaman made his Mavericks debut as a reserve, but the spark off the bench came from Vince Carter. The 14-year veteran got the crowd going with a powerful dunk and did it again later with a spectacular blocked shot.
Ramon Sessions led Charlotte with 22 points.