But the Pacers got into an offensive rhythm and with 31 seconds took the lead en route to a 98-93 come from behind win at Bankers Life Fieldhouse. Indiana erased the double-digit deficit with an 18-3 run.
David Sloan scored 12 of his 15 points for the Pacers in the fourth and gave Indiana the lead for good, 95-93, when Allen took the inbounds pass and immediately found him cutting through the lane for the layup.
Indiana shot an impressive 75 percent from the field in the fourth, hitting 12 of its 16 shots.
Chris Copeland, in his second start of the preseason, made the most of his 31 minutes by scoring a game-high 22 points to lead Indiana. David West added 16 points and George Hill had 10.
Richard Jefferson and Gal Mekel led Dallas with 19 points each. Al-Farouq Aminu contributed a double-double with 11 points and 12 rebounds.
Jefferson and West matched each other shot-for-shot early in the third until West missed a putback from under the bucket, which was blocked by Al-Farouq Aminu.
West fell to the floor grabbing at his right ankle. He was helped off the court and went straight to the locker room. He did not return for the Pacers and was diagnosed with a right ankle sprain according to the Pacers staff.
Pacers: Indiana was without Rodney Stuckey and C.J. Watson who were both out with foot soreness. Luis Scola and Shayne Whittington were out for rest per Pacers coach Frank Vogel. . Indiana shot just 18.9 percent from the field in the second quarter.
Mavericks: Dirk Nowitzki sat was out of the lineup, listed as coach's decision. . Dallas out shot the Pacers 43.5 percent to 42.5 percent. But, they only shot 20 percent from beyond the arc in the fourth quarter.
Indiana's Lavoy Allen hit a jumper with 7:35 to play to spark the Pacers fourth-quarter scoring run. Indiana outscored Dallas 37-19 in the final period.
The Pacers will travel to Minneapolis to face the Timberwolves on Tuesday.
The Timberwolves play host to the Memphis Grizzlies on Monday.