Dallas trailed by eight at the intermission, but shot 63 percent from the field in the second half, put together a 17-4 run in the fourth quarter and won for the fifth time in six games.
The Mavericks' only setback in that stretch was a one-point defeat at the hands of San Antonio.
Dion Waiters had 21 points to lead Cleveland.
Vince Carter scored seven points for Dallas and became the 33rd player in NBA history to reach 8,000 field goals in a career.
Dog comes home gnawing on human bone
Julius Randle breaks leg during NBA debut