Shawn Marion had 16 points and Jason Terry 13 to help the Mavericks to their fifth victory in six games.
Nowitzki rolled his right ankle in the second quarter of Wednesday night's win at Memphis, sitting out the final 3½ minutes of the first half. He participated in Friday morning's shootaround, and felt good enough to be in the starting lineup.
Thaddeus Young scored 17 points and Spencer Hawes had a season-high 14 for the Sixers. Andres Nocioni also scored 14 for Philadelphia.
The Mavericks got big nights from their centers, with Brendan Haywood contributing 17 rebounds and Tyson Chandler providing 11 points and 12 boards before fouling out with 2:14 left.
Jason Kidd recorded his 11,000th career assist with 9:51 left in the first quarter on Chandler's alley-oop dunk, and the Mavericks carried a 31-22 lead into the second quarter. Dallas held a 55-48 halftime advantage.
Kidd finished with 10 points and eight assists.
After trailing by as many as 10 in the first half, the Sixers tied it at 71 on Jrue Holiday's layup with 2:25 left in the third quarter.
But Barea converted layups on consecutive possessions and Haywood hit a free throw with less than a second left in the third quarter to give the Mavericks a 78-75 edge.
Barea worked inside for two more short-range baskets during a 7-2 run to open the final quarter, giving Dallas an 85-77 edge. Dallas went on to lead by as many as 14 down the stretch, coasting to its sixth straight home win over the Sixers.
Notes: Mavericks G/F Caron Butler (14.7 ppg., third on the team) missed his second consecutive game due to back spasms. ... Sixers G/F Andre Iguodala was back in the starting lineup after sitting out two games with right Achilles' tendinitis. ... G Lou Williams remains in the Philadelphia rotation despite a separated left shoulder. ... The Mavs have won eight of their last 10 against the 76ers.