Mayo hit 3-pointers from the right wing and then the left wing in the third quarter. He hit another from long range to put Dallas up 70-67 with 5½ minutes left in the period, breaking the only tie of the second half.
After Sasha Pavlovic beat the shot-clock buzzer with a 3-pointer to get Portland within 75-73, Collison passed to Vince Carter for a 3-pointer. Mayo added another 3 before the end of the third to stretch the lead to 83-77.
Mayo scored seven points in the first 5 minutes of the game and had 12 of the Mavericks' first 22 as they built an early 10-point lead.
"He's one of the hardest workers on this team. He's constantly shooting every day," Collison said. "That 3-point shot is like a mid-range shot to him. ... If he continues to shoot like that, we're all going to have a very good season."
Portland got even at 43 on two free throws by Lillard before Aldridge's three-point play gave the Trail Blazers their first lead, 46-45, with 4:16 left in the first half.
But Lillard shot only 2 of 13, including 1 of 8 on 3-pointers.
"It was a tough night. I got some good looks, didn't make shots," Lillard said. "That's pretty much it. I tried to stick with it. I got some early fouls and that took the rhythm out of it for me."
Notes: Mavericks F Shawn Marion left in the third quarter with a strained knee. It didn't appear that the injury was serious. ... There was a moment of silence before the game in memory of ESPN radio announcer Jim Durham, who died last weekend at his home in Texas. Durham was the Mavericks' television play-by-play man from 1993-2001. ... Another former Mavericks assistant coach brings his team to the American Airlines Center on Wednesday night. Dwane Casey is in his second season as Toronto's head coach.