Jrue Holiday contributed 18 points along with seven assists, but missed two make-able jump shots in the final 1:04, allowing Dallas to pull within two points on a pair of Vince Carter baskets.
The Mavericks' O.J. Mayo had a chance to tie the score on a pair of foul shots with 2.5 seconds left, but missed the first and intentionally missed the second to produce a rebound.
The ball was tipped to Jae Crowder, who missed a desperation 3-pointer for Dallas at the buzzer.
Thaddeus Young had 20 points for Philadelphia.
Carter finished with 15 points for the Mavs.