"It was a diagrammed play and we worked it to perfection," Marion said. "This is our last preseason game and we wanted to play with energy."
Dallas ended the game on a 14-4 run in the final 4:03. Marion's basket was the first time the Mavericks led since it was 36-35 with 6:31 left in the first half.
"The manner in which we lost the game was disappointing," Rockets forward Shane Battier said. "You have to finish games out, we didn't execute down the stretch."
Rockets coach Rick Adelman missed the game with flulike symptoms. Assistant coach Elston Turner led the team in Adelman's absence.
"I don't put too much stock in exhibition wins," Dallas coach Rick Carlisle said. "But we won this game like we've won a lot of games the last couple years with grit, know-how and resourcefulness."
"We're still a work in progress," Battier added. "We've had a lot of key players out during the preseason."
Mavericks center Tyson Chandler missed the game with an injured right thumb. Carlisle said Chandler is optimistic that he will be available for the team's season opener on Wednesday against Charlotte.
Kevin Love launches a full-court pass to LeBron James for the ferocious one-handed dunk, putting the Cavs up 31.
Cleveland busts open Game 5 early as they end the first quarter on a 17-3 run against the Raptors to stretch their lead to 18 points.
Jalen Rose and David Jacoby break down Draymond Green's performance against the Thunder and offer some advice.