Dallas heads into the long residency the winners of two straight and four of its last five. Despite the strong play, Dallas is 1 1/2 games behind the Golden State Warriors for the sixth seed in the Western Conference, and just a half-game in front of the Memphis Grizzlies, who are eighth.
The Mavs' second consecutive victory was impressive, dispatching the Oklahoma City Thunder, 109-86, Sunday in Oklahoma City.
Shawn Marion led the sharp-shooting Mavericks with 19 points, followed by Vince Carter, who netted 18 points, and Dirk Nowitzki, who added 17. Samuel Dalembert chipped in 10.
Dallas shot 53.3 percent from the field and 13-of-24 from behind the arc in a surprising rout.
Jose Calderon took advantage of OKC star Russell Westbrook's absence with 16 points, seven assists and five rebounds for Dallas.
"They were down a great player so we caught a break there," Mavs head coach Rick Carlisle said. "It's a game we needed, so it's a plus for us."
The Celtics will complete a short road trip Monday night and it started poorly. Boston fell to the New Orleans Pelicans, 121-120, in overtime Sunday night.
It was Boston's fourth consecutive loss.
Jeff Green had a team-high 39 points and grabbed six boards and Kris Humphries chipped in 16 points and 12 rebounds for the Celtics, who have lost six of their last eight. Jared Sullinger and Avery Bradley contributed 14 and 12 points, respectively, with Sullinger adding nine rebounds.
Humphries sent the game to overtime after Anthony Davis made a jumper with 1.4 seconds. In the extra session, the Pelicans had a four-point cushion, but Green converted a three-point play. New Orleans played keep away over the last 5.7 seconds to secure the victory.
"Yeah that's a tough one to swallow," admitted Sullinger. "(Kris) Humphries hitting that big shot to send it into overtime, we thought we could win. In the end we came up short."
The Mavs beat the Celtics in Boston on Feb. 9 and have won six of the last seven in the series. Dallas has won three in a row as the host against the Celtics.