The Mavericks hit seven 3-pointers to pull away in the fourth quarter, including two in a row from Nowitzki followed by one from Ellis for a 118-102 lead with 1:18 remaining.
Ellis joined the Mavericks with questions about his efficiency on offense, but answered those concerns at least for one night. He was 11-of-17 from the field and had eight assists. The only downside was seven turnovers.
Nowitzki finished 8-of-14, including 4-of-6 from beyond the arc, after missing last year’s opener and the next 26 games following right knee surgery.
Jeff Teague led Atlanta with 24 in Budenholzer’s first game, which came against a familiar opponent since he was a longtime assistant to Gregg Popovich in San Antonio.
The Mavericks opened with a win over an Eastern Conference playoff qualifier from last season after they missed the postseason in the West for the first time since Nowitzki’s second season in 2000.
Until Nowitzki and Ellis put it away, the Hawks stayed close in their first game without Josh Smith since he left in free agency.
Teague also had nine assists, and Paul Millsap finished with 20 points on 9-of-15 shooting operating inside. DeMarre Carroll had 14, and Al Horford scored 11.
Jose Calderon, Ellis’ new backcourt mate and another of the nine new faces in Dallas, struggled offensively until the fourth quarter, when his first field goal was a 3-pointer that answered one on the other end by Carroll to put Dallas up 107-97.
Calderon had five points and a game-high 11 assists, including one on an alley-oop dunk by Vince Carter that started a 17-2 run to put Dallas ahead 84-72 late in the third quarter. Carter added a 3-pointer from several feet behind the arc later in the run to extend his streak to 26 games with at least one from long range dating to last season.
Cartier Martin hit a 3-pointer to pull Atlanta within 84-76 going in the fourth quarter.
Nowitzki looked comfortable right away, making his first three shots and getting a couple of assists early before finishing the first half with 13 points.
Ellis had a game-high 15 points before the break with a mix of jumpers and drives to the basket. But he had two of his four first-half turnovers during a 7-0 Atlanta run that pulled the Hawks even at 47-all.
The Hawks held the first lead at 2-0 for 25 seconds, but didn’t go in front again until Millsap scored for a 55-53 lead with 11 seconds left in the first half.
NOTES: Atlanta G Dennis Schroder of Germany made his debut against Nowitzki, just as Nowitzki did on Feb. 5, 1999, against the German star at that time, Detlef Schrempf. Nowitzki was 20 when he played that game in Seattle, just as Schroder is now. Schroder was the No. 17 pick in this year’s draft by the Hawks. He had five points and five assists. ... Nowitzki became the 27th player in league history with 40,000 minutes played. He needed 25 and finished with 33.