"It was cool," said Amundson, who finished with 13 points on 5-of-7 shooting. "It was a lot of fun being out there. We all came in and gave the team something different."
Amundson was on the floor at the expense of Amare Stoudemire, who had 22 points before spending the entire fourth quarter on the bench for what he said was "the first time in my life but it's all good."
Phoenix coach Alvin Gentry said Stoudemire was sidelined not for anything he did or didn't do but because of the energy the subs brought to the floor.
"I wouldn't read anything into that at all," Gentry said. "If you go in there he's the happiest guy. For all that's been said he's been a great teammate. He understands things were going well with Lou."
Steve Nash added 19 points and 11 assists, and Jason Richardson had 17 points to help the Suns snap a three-game losing streak against the Mavericks.
"We just need something to lift our spirits a little bit," said Gentry, whose team had lost seven of nine entering the game.
"Their bench outplayed us all night," Terry said. "Clear as day and it can't happen. They outplayed us. It's unbelievable to me that we've come halfway through the season and we still look like we're searching in the fourth quarter."
Dallas led by eight early in the fourth before the Suns' reserves started the rally.
Earl Clark hit his first career 3-pointer to pull Phoenix to 92-90 with 9:41 left. Dallas made it 98-93 on Jose Barea's driving layup with 7:25 to go, but didn't hit another shot from the field until Shawn Marion's short jumper with 3:31 left.
"We made people shoot the shots they didn't want to shoot," Dudley said.
Amundson gave Phoenix its third lead, 99-98, on a driving dunk with 5:25 remaining, Dudley hit two free throws, and Amundson added a free throw to put Phoenix ahead 102-98 with 4:33 left. Marion's jumper pulled Dallas within two, but Nash hit a 3-pointer, and Amundson scored on a scoop shot with 1:46 to go to make it 107-102.
"We've got a six-point lead going into the fourth quarter and we've got to do a better job of executing and defending," said Mavericks coach Rick Carlisle. "It's as simple as that. Their level of aggression was higher than ours."
Dragic finished with 13 points, and Dudley has eight.
Dallas lost for the fourth time in 21 games when scoring more than 100 points. ... Stoudemire, who broke the 20-point mark for the first time in four games, did not have a defensive rebound in 27 minutes of action. ... Phoenix is 11-2 at home against the Western Conference. ... The Mavericks trailed for two possessions and 40 seconds over the first three quarters. ... Marion was making his third trip back to Phoenix with his third team since he was traded by the Suns to Miami midway through the 2007-08 season in the Shaquille O'Neal deal.'Neal