However, the Mavs could not overcome the mistakes, and they went down 117-115.
Dallas took its first and only lead with under two minutes to go in regulation, when Derek Fisher hit a clutch three, but the Celtics came back to tie the game. After several ties throughout the two extra frames, the Mavs just didn't have enough gas to push back out in front.
Free throws sealed the game for the Celtics.
Dallas is now back at 11-11, ending a three-game winning streak. The Mavs have beaten some high-profile teams this year, such as the Los Angeles Lakers and New York Knicks, but now they are just 1-8 against teams above .500.
O.J. Mayo once again led the Mavs in scoring with 24 points, but had a season-high nine turnovers. Darren Collison had a confidence-boosting game with 20 points, six assists, and five rebounds, but his turnover on an inbound pass late in the second overtime all but sealed the loss for Dallas.
The Mavs travel to Canada to take on the Toronto Raptors on Friday night.
Tags: Basketball, Boston Celtics, Dallas, Dallas Mavericks, Darren Collison, NBA, O.J. Mayo