J.J. Hickson's jumper made it 41-34 for Portland, but Bryant answered for the Lakers with a 3-pointer. Batum's fast-break jam gave the Blazers a 46-40 lead and Portland went into halftime with a 62-57 lead.
Portland took its momentum into the second half, going up 72-64 on another dunk by Batum. Sasha Pavlovic's 3-pointer gave the Blazers an 88-76 lead just before Howard was called for his fourth foul.
Matthews' jumper made it 102-83 in the fourth quarter. Batum had a 3-pointer to make it 108-94 as the game slipped out of reach for the Lakers.
Batum's opener comes after an uncertain offseason as a restricted free agent. The Blazers got into a poker match with the Timberwolves over the 23-year-old Frenchman, eventually matching Minnesota's four-year offer sheet worth more than $45 million.
Batum, like the rest of the Blazers, was trying to keep the victory low-key.
"This was just one game, just one game," he said. "It was a really good win, but we've got to focus on the next game on the road."
Portland visits Oklahoma City on Friday night.
The Blazers wore new red uniforms for the opener and encouraged fans to wear red, but the crowd was nonetheless sprinkled with plenty of Lakers gold. Among them was a fan that lifted a sign reading, "I love Steve Nash."
"The morale is fine, but nobody wants to lose," Lakers coach Mike Brown said. "We've just got to focus on what it will take for us to get a win. That's defense, first, and then, obviously, we've got to take care of the basketball."
NOTES: The Blazers declined team options for next season on guards Elliott Williams and Nolan Smith, and forward Luke Babbitt, to maintain salary cap flexibility. All three will become unrestricted free agents at the end of the season, but the Blazers will retain their Bird rights. ... Portland added 10 players to the roster of the team's NBA D-League affiliate, the Idaho Stampede, including training camp participants Coby Karl, Justin Holiday and Dallas Lauderdale.