Like their visit to Houston to face Dwight Howard on Monday, the Mavericks (4-3) had something resembling a dress rehearsal with Nowitzki, Ellis and Jose Calderon playing together in front of the home crowd for the first time.
The Mavericks finish the preseason Friday night against Indiana before playing the Hawks again in the season opener next Wednesday.
Vince Carter and Jae Crowder had 3-pointers in an 8-0 run bridging the third and fourth quarters to put Dallas up 79-69. The Hawks got within five in the fourth before Crowder hit another 3 to push the lead back to 11 in the last 2 minutes.
Nowitzki, Ellis and Calderon all played more than 20 minutes for the second straight game, and were all on the court with Dallas nursing a six-point lead early in the fourth quarter.
Nowitzki, who was ejected for a flagrant foul late in the third quarter against the Rockets, was 7 of 17 from the field and 1 of 6 from 3-point range.
Ellis had five assists and was 5 of 13 from the field after scoring eight points on 3-of-13 shooting against Houston.
Atlanta's Elton Brand had seven points and six rebounds in his return to Dallas after playing 72 games with 18 starts in his only season with the Mavericks. Jared Cunningham, a first-round pick acquired by Dallas in 2012 and traded to the Hawks on draft night this year, scored 14.
Devin Harris, who spent last season with the Hawks, is back in Dallas after starting his career with the Mavericks nine years ago. He won't see the Hawks early in the season while he recovers from offseason toe surgery.