Josh Smith filled the stat sheet with 23 points, nine rebounds and seven assists, and Atlanta used a quick start to dismantle Dallas, 106-89, to cap the abbreviated regular season.
Jeff Teague added 17 points and Joe Johnson 15 for the Hawks (40-26), who on the final night of the regular season gained home-court advantage for their Eastern Conference quarterfinal series with the fourth-seeded Celtics. Game 1 of that series is Sunday at Philips Arena.
It was during their last playoff meeting, in the 2008 Eastern Conference quarterfinals, when the Celtics won four times at home, winning Game 7 by 34 points.
"It's real big," Smith said of getting home-court advantage. "We experienced that when we first made the playoffs five years ago and we had to play against a rowdy crowd in Boston. Having home-court advantage is definitely key."
The Mavericks (36-30) will start defense of their NBA championship with a rematch from 2011 against the Thunder. Oklahoma City, winners of the Northwest Division, lost to Dallas in five games last year in the Western Conference finals.
"Well they're a great young team, we're a veteran team," Mavericks coach Rick Carlisle said. "We know the kind of capabilities they have as a team and we know what we have to do to play at our level. It's a great matchup. There's geographic interest. The teams are close together.
"We had a real intense series with them last year. It's a tough matchup, but we're looking forward to it."
Dirk Nowitzki scored 22 to pace the Mavericks, who dropped four of their last six contests.
Dallas came into the regular season finale needing a win and a Nuggets loss to move to the No. 6 seed, but the Mavericks let the Hawks shoot 16-of-23 from the field in the opening quarter. Smith scored 12 in the period, as Atlanta bolted to a 38-21 lead after 12 minutes.
Included in that quarter was a 13-0 run, keyed by a Kirk Hinrich three-pointer and finished by Smith's jumper. The latter bucket extended the margin to 17-6 with 6:55 left in the period and the largest lead in the quarter was 23 at 36-13 on a three-ball from Willie Green with 1 1/2 minutes remaining.
The Hawks, who won five of their last six games, held a comfortable 60-44 lead at the half and were up 86-72 after three quarters. The closest Dallas got was 12 early in the fourth.
The Mavericks are 20-12 all-time in games on the final day of the regular season. They had won five straight and eight of their last nine season finales prior to Thursday...Hinrich scored 12 points...Atlanta shot 52.9 percent.