Winning their 12th consecutive home game, the Celtics outscored the Blazers 41-15 in the final 2:52 of the second quarter and throughout the third. Boston cruised to 116-93 win that ended Portland's six-game road winning streak and handed the Blazers only their third loss in the past 15 games overall.
And the Celtics ran away with this one after trailing by 12 points in the first quarter.
"That just shows the relentlessness that we have," guard Marcus Smart said after coming off the Boston bench to produce 15 points and 11 rebounds, the latter matching his career high. "They could have run away with that game. We dug down deep, we stuck to what we knew, we listened to Coach Brad (Stevens) and came out with the victory.
The home winning streak is Boston's first 12-gamer since 2007, and the Celtics (37-25) have the floundering New York Knicks coming to town Friday night to end a five-game homestand.
The win was also the Celtics' 15th in the past 19 games overall.
Isaiah Thomas scored 30 points to lead the Celtics, who also got 15 points and 11 rebounds from Jared Sullinger. Avery Bradley scored 17 points, Jae Crowder added 12 points and six rebounds, and Jonas Jerebko came off the bench to contribute 10 points and six boards.
"They got after us. I think it's that simple," Portland's Damian Lillard said. "We just weren't good enough.
"We didn't do a lot of the things that we've been doing at the level that we've been doing them. You can't go out there and let a team at home compete harder than you and not execute the game plan coming in."
Lillard and fellow guard CJ McCollum, who came in averaging a combined 46.3 points per game, totaled 37 points. McCollum, who had 17 but missed eight consecutive shots after starting the game 5-for-5. The pair shot 13-for-30, including 6-for-13 on 3-pointers.
Lillard, who had 20, had scored at least 30 points in eight of the previous nine games.
The Trail Blazers, falling to 3-10 in the back end of back-to-backs, built their 12-point advantage in the first 8:24, but the Celtics had their deficit down to three by the end of the first quarter and then took a 36-35 lead 90 seconds into the second.
Boston trailed by two with 3:09 left in the half, but then went on an 11-3 run the rest of the half to go up by six before exploding out of the gate in the third quarter.
"I wouldn't want to use that as an excuse," Portland coach Terry Stotts said of the back-to-back. "We got off to a good start. It seemed like a fast-paced game. Certainly they had a lot of bounce."
Stevens believed Portland's fatigue was a factor, though.
"I think sometimes you catch a team on the right night," the Boston coach said. "This is their fourth game out east, and they're playing at a really high level, back-to-back and everything else, and our guys were geared up for it."
Said Sullinger, who fashioned a couple of spin moves that ended in dunks: "We know that they played a game last night ... I always tell my teammates that it's 50/50, you never know if they're going to come in here or be rolling or they might come in here and be trerd. Our mindset was to just stay on them the entire game and try to make everything hard on them."
NOTES: The game matched up the February coaches of the month, selected Wednesday -- Portland's Terry Stotts (West) and Boston's Brad Stevens (East). ... Blazers F Noah Vonleh and G Pat Connaughton, both Massachusetts natives, had friends and family at the game. "This is my first game actually playing (in Boston). I'm starting, too," Vonleh said before scoring six points. "It's going to be good playing in front of the home crowd." Connaughton recorded seven points late, receiving audible crowd support when he scored. ... Portland came in leading the NBA with an average of 112.8 points per game since Jan. 22, while the Celtics' 111.4 over that same stretch was third best in the league. ... F Kelly Olynyk (shoulder separation) will be re-examined Monday. "(There is) a chance he'll up his activity Monday -- whatever that means," Stevens said.