The five Lakers starters combined to outscore Ellis by just two points (32 collectively), led by Pau Gasol with 10.
Nick Young led the Lakers with 21 points off the bench. Jordan Farmar (11), Jodie Meeks (11) and Chris Kaman (10) contributed double figures, but it was the Lakers' defense that was an issue for most of the night.
The Mavericks shot 52.1% from the field and 13 for 27 from three-point range. Dallas also out-rebounded the Lakers, 50-35.
The Lakers went a roundabout way to trim two points off the Mavericks' 19-point halftime lead. Dallas jumped ahead in the third by 30 (90-60) before the Lakers whittled that lead to just 17.
Monta Ellis led all scorers with 26 points on 9-of-12 shooting along with eight assists. Five Mavericks hit double figures as the team shot 52% from the field with just six turnovers.
The Mavericks pushed their lead over the Lakers to 20 before Dirk Nowitzki scored a single point.
A late 7-0 run helped the Lakers climb within 13, but the Mavericks quickly responded before the half, pushing their lead back to 19.
Chris Kaman led the Lakers with 10 points off the bench. The team shot 40.4% from the field.
The Mavericks shot 48.1% while holding a 19-10 rebounding advantage.