Dallas led 88-83 after a jumper by Nowitzki, but Ellis answered with a three-point play and Dunleavy scored on a layup off a turnover by Nowitzki — Ellis' sixth steal and one of 20 Dallas turnovers — to tie the score at 88.
"We built two or three eight-point leads and then proceeded to immediately let those leads go away," said Dallas coach Rick Carlisle. "The inability to sustain has been our nemesis all year."
The Mavericks went on an 8-0 run to finish the third quarter and erase what was Milwaukee's biggest lead to the point — four. Brand had a pair of jumpers and Nowitzki and Mayo had one apiece while the Bucks went the last 4 minutes of the quarter without scoring.
The last six minutes of the first half were a series of runs that ended with Dallas leading 49-44. Led by six from Brandan Wright, the Mavericks went on a 14-2 spurt for a 41-31 lead before the Bucks scored 10 straight to pull even.
Dallas went on an 8-0 run started by two buckets from Collison, who led the Mavericks with 11 points and four assists before halftime, but Dunleavy hit a 3-pointer with 2 seconds left to pull the Bucks within five.
Drew Gooden, who hadn't played in six games and sat out 15 of the previous 16, had eight points in the first half for the Bucks, one shy of his season high. He was the Milwaukee TV crew's choice for the halftime interview before going scoreless in the second half.
NOTES: The Bucks suspended C Samuel Dalembert for the Dallas game for an unspecified violation of team policy. He was relegated to a backup role after the emergence of Larry Sanders, although he did have 35 points, a career high, and 12 rebounds off the bench Feb. 5 against Denver. ... Mavericks G Anthony Morrow played just the final 3.9 seconds in Sunday's loss to the Lakers, his first game in uniform after coming over in a deadline trade with Atlanta. He got in the first quarter against the Bucks, and was 0 of 2 from the field in 3:41. ... Nowitzki drew a duck and a scowl from Carlisle when an errant baseball pass on an inbound play flew over Carlisle's head out of bounds for a turnover 29 seconds into the game.