PORTLAND, Ore. -- The Boston Celtics' game plan was simple Thursday night at the Moda Center: Blanket Damian Lillard and CJ McCollum and make their teammates beat them.

It was the perfect time for Al-Farouq "Chief" Aminu to come through with the game of his career for the Portland Trail Blazers.

The veteran small forward scored a career-high 28 points, grabbed nine rebounds and blocked three shots as the Trail Blazers pulled out a 116-109 victory over the Celtics.

"Chief turned the game around for us," said Lillard, who was held to 14 points on 3-for-16 shooting. "Not just because of the shots he made, but defensively, he was coming from the weak side, blocking shots, deflecting passes.

"He hadn't been shooting the ball all that great, but tonight when we needed him, he rose up and knocked 'em down. He was our MVP."

McCollum added 17 points with eight assists, and Gerald Henderson came off the bench to contribute 15 points, five rebounds and five assists for the Trail Blazers, who won their third consecutive game overall and sixth in a row at home.

Isaiah Thomas scored 22 points but made only six of 21 shots from the field and had five turnovers for the Celtics, who lost their second straight. Reserve guard Evan Turner had 14 points for Boston.

Aminu, whose previous career high was 20 points, made 11 of 19 shots from the field, including a career-high six from 3-point range (on 11 attempts).

"(The Celtics') game plan was to make sure (Lillard and McCollum) had two defenders on them at all times.," Aminu said. "They made the right reads, but that left me open. I just felt I was doing what I'm supposed to do."

Boston coach Brad Stevens said, "His 3-point percentage is pretty good, but it's the volume plus percentage that you look at. If he's going to shoot 11 threes and Lillard is going to go 3-for-16, you hope you have a better chance to win."

Thomas scored 13 first-half points and Turner added 12 to fuel Boston to a 58-54 halftime lead. Mo Harkness had nine points and eight rebounds for Portland at the break, but he didn't score in the second half.

The Celtics (43-32) stoked their lead to 75-64 midway through the third quarter. The difference was 81-71 when the Blazers used a 10-0 run to tie it late in the period. Boston carried an 83-81 edge into the final quarter.

Aminu sank back-to-back 3-pointers to start the fourth quarter to give Portland an 87-83 lead. With Henderson leading the way, the Blazers built the margin to 102-89 with 8:02 to go. Boston responded with an 8-0 run to close within 102-97. Thomas knocked down a 3-pointer to make it 104-102 with 3:35 remaining.

McCollum's driving layup increased Portland's lead to 107-102, but Thomas made a pair at the line to close it to 107-104 with 2:18 left.

Amir Johnson's tip-in cut the gap to 108-106 with 1:54 remaining, and Jae Crowder's 3-pointer gave Boston a 109-108 lead with 1:08 to play. However, McCollum sank a fadeaway, then set up Aminu on a breakaway dunk to push the Blazers ahead 112-109 with 49.2 seconds left.

Lillard went 4-for-4 at the line in the closing seconds to wrap things up for Portland (40-36).

"It was important to get this one," Portland coach Terry Stotts said. "We've done a good job protecting home court the second half of the season. For what we want to accomplish this season, we needed to win."

NOTES: F Jae Crowder, who missed the previous eight games with an ankle injury, was back in Boston's starting lineup. He finished with 13 points and 10 rebounds in 35 minutes. "He's a winning type of player," Portland coach Terry Stotts said. "He does whatever they need him to do."... The Celtics lost for just the fifth time in their past 11 visits to Portland. Boston defeated the Blazers 116-93 at the TD Garden on March 2. ... Since joining Portland's starting lineup on March 23, F Mo Harkless was averaging 13.0 points and 5.7 rebounds while shooting .541 from the field through four games. ... Portland entered the night 20-10 in the last 30 games, tied for the fifth-best record in the NBA over that duration. The Blazers improved to 15-2 in their past 17 home contests. ... Boston went into the game leading the league in opponents' turnovers (16.4 per game) and 3-point field goal percentage (.328) and second in steals (9.2 per game).