Chandler Parsons scored 29 points, including a key 3-pointer to help Dallas hang on after going up by 30 before halftime for the second time in two home games, and the Mavericks beat the Boston Celtics 118-113 Monday night.
Avery Bradley had a chance to tie with three free throws when he was fouled on a 3-pointer by Monta Ellis with 39 seconds left after Boston trailed by 31 in the second quarter. But he missed the second one.
After Ellis put Dallas back up by three at 116-113, Parsons won a jump ball with Jared Sullinger, tipping it to Ellis, who was fouled by Rajon Rondo on a drive and made both free throws.
Dirk Nowitzki had 27 points. Jeff Green led the Celtics with 35, and Bradley had a career-high 32.
The Mavericks shot 73 percent in the first quarter and had at least 66 points at halftime for the third straight game, all wins since a season-opening loss at San Antonio.
But Dallas cooled off and couldn't shake Boston the way it did Utah after going up by 30 before halftime and losing more than half the lead in an 18-point win in the home opener.
The Mavericks had pushed a 107-104 lead back to 10 points on a 3-pointer and an easy layup by Parsons after a turnover by Rondo. But the Celtics got the deficit back down to three a little more than a minute later before Ellis undercut Bradley on a 3-point try.
Even with Bradley's missed free throw, Boston had a chance to tie again the next time down when Green missed a 3 and Parsons and Sullinger ended up in a jump ball after a mad scramble on the floor.
The Celtics got within three the first time on a 3-pointer by rookie Marcus Smart in his return to the Dallas area, where he starred for a high school team that won two state championships. He had seven points, six rebounds and three assists.
Boston went 11 of 31 from 3-point range two nights after going just 1 of 25 from beyond the arc in a loss at Houston.
The Celtics started their rally by hitting eight of their first nine shots in the third quarter. The hot start included a pair of 3s from Green, who was 14 of 28 from the field. Bradley was 13 of 22, including 4 of 6 on 3-pointers.
The Mavericks have been outscored by double digits in three of four third quarters this season.
Celtics: Smart had dozens of supporters from his Dallas-area high school at his first pro game close to home. They wore "We are 4 Marcus" T-shirts with his No. 36 inside a shamrock. Smart played at Marcus High School in the suburb of Flower Mound.
Mavericks: Chandler had his first double-double since returning to Dallas with 10 points and game-high 12 rebounds. ... Forward Al-Farouq Aminu left the game in the second quarter with a left knee injury.
Celtics: Return home to face Toronto on Wednesday after a two-game Texas swing to open road schedule.
Mavericks: Get two days off before back-to-back road games in Portland and Utah.