Mayo hit 8-of-12 field goal tries, including a pair of 3-pointers, and also notched eight assists and three rebounds.
Dallas shot 54 percent from the field as a team and scored 31 points in the fourth quarter to keep the 76ers at bay.
The Mavericks led 57-52 at halftime but were outscored 22-19 in the third quarter and led by 2 points at the start of the fourth.
Gal Gadot cast as Wonder Woman for 'Batman vs. Superman'
Man spent 15 hours in jail for plugging electric car into an outlet at a school