Jack had 17 of his 22 points in the second half for Portland, which shot 51 percent and has won two in a row at home after an 0-3 road trip to open the season.
For the first half the Blazers seemed to be on their way to their fourth consecutive loss to Memphis at the Rose Garden. But they shut down Gasol, who attempted just one shot in the second half, and Roy keyed an 11-0 third quarter rally that all but erased Memphis' 12-point halftime lead. Roy scored 18 in the second half and Jack hit 5 of 6 shots after halftime.
It was pretty much the way Blazers coach Nate McMillan was hoping.
"We want the ball in the hands of our best player," McMillan said. "That's what other teams do. In Denver, the ball is in Carmelo (Anthony)'s hands. The Lakers put the ball in Kobe (Bryant)'s hands, and we want Brandon to have it."
Defense was the difference in the second half and the Grizzlies withered, making just 13 of 41 shots after shooting 50 percent before halftime.
While Portland blanketed Gasol, the Grizzlies didn't do the same to Aldridge, who so impressed the Blazers as a rookie last year that they traded away Zach Randolph to make room for him at power forward. Aldridge showed his range, scoring both down low and on jumpers several feet past the free-throw line. He shot 12-of-20 and made 6-of-7 free throws.
Gasol made eight of his first nine shots, including two free throws at 7:33 in the second, giving Memphis a 40-27 lead. But the Blazers switched to a double-team and neutralized Gasol, who didn't attempt a shot again until the middle of the fourth.
"They got a flow and we were with our hands down," Gasol said. "We should have done the things we did in the first half."
Memphis took a 12-point lead into the break. Roy, who had just four points in the first half, woke up and led Portland's rally.
"We showed tonight how we are not going to get down on ourselves when we get behind," Aldridge said. "When it gets tough, we're going to get tough."
After Webster knocked in a 3, Roy fed Channing Frye on the break for layup. He then stole the ball on the next possession, converting a three-point play off a give-and-go with Steve Blake. Soon after Roy found Aldridge on a fast break for a three-point play that cut the score to 63-62.
Aldridge gave the Blazers their first lead since the first quarter, scoring to make it 86-84 with 7:17 left in the game. Roy scored twice to make it 93-65, but Gay, who was 13-of-24 and carried the load for Memphis in the second half, responded with an immediate 3-pointer.
Aldridge hit a jumper at the top of the key to give the Blazers a 97-90 lead with 3:11 to go.
"They did a good job of taking the ball out of (Gasol's) hands," Memphis coach Marc Iavaroni said. "The pressure was on other guys to make shots and make plays, so it was a good strategy."
Blake, who replaced Jack as Portland's starting point guard this week, had eight assists for the Blazers. As the Blazers went with a smaller lineup in the second half, the Blazers paired both Blake and Jack in the backcourt.
Meanwhile, the Grizzlies' point guard situation seems in flux, too, with Damon Stoudamire playing just 17 minutes, scoring one point and sitting long stretches.
Backup point guard Lowry ran the Grizzlies' offense for much of the game, scoring 14 points in 30 minutes, and rookie Mike Conley Jr. had eight points in 17 minutes.
- Forward James Jones is out indefinitely with knee trouble for the Blazers, McMillan said. Jones will stay on the active list though, because Josh McRoberts, Greg Oden and Darius Miles are all injured, too.
- Conley and Oden were teammates at Lawrence North High School in Indianapolis and Ohio State.
- Portland outscored Memphis 25-15 in the third quarter. The Blazers had scored 15 points in each of its last three third quarters.