"Fans, people around the building look at other teams and tend to think they are not supposed to score or even be in the game," Allen said. "They [Wizards] are getting paid the same as we are and I told the guys at halftime that we need to make them more uncomfortable."
Boston trailed 79-66 with 6:11 remaining and responded with a 20-4 run to close out the game with eight points from Allen and six from guard Rajon Rondo.
"Well we choked. Six minutes to go and we're up 13 and we start talking to Garnett, start talking trash and everything else," Wizards coach Flip Saunders said. "Got Garnett and those guys juiced up."
The Celtics cut the deficit to 79-76 before JaVale McGee dunked in a Randy Foye miss for Washington with 2:38 left, but the Celtics scored six more capped by Allen's 3-pointer for an 82-81 Boston lead with 1:33 remaining.
On the next possession, Foye hit a jumper in the lane as the Wizards regained the lead 83-82.
With 35 seconds remaining, Foye missed a 3-pointer and a scramble for the rebound ensued before Garnett grabbed the ball and called timeout. Allen then made it 85-83 on his 3-pointer from the corner and Garnett added a free throw before Al Thornton's 3-pointer went off the rim at the buzzer.
"We've lost so many of these where we played poorly and lost," Celtics coach Doc Rivers said. "It was nice to play poorly and win. I just wish we could have played the first 40 minutes, like we played the last eight."
Thornton scored 24 points and grabbed 11 rebounds while Andray Blatche added 23 points and nine rebounds for Washington.
"We were so discombobulated," Saunders said. "You have a veteran team that knows how to close out games against a young team and instead of letting a sleeping dog lie, we juiced up their energies."
Garnett finished 0 for 7 from the floor but added 10 rebounds while Paul Pierce had 17 points. It was the first time since Jan. 27, 1996, against New York when he was playing for Minnesota where he was held without a field goal (0 for 5).
"Once our defensive intensity picked up, it changed the whole ballgame, making them do things they didn't want to do," Pierce said.
Allen and Rondo led a 12-4 run to close out the third and combined to score the last 17 points of the quarter for Boston and narrow the deficit to 66-62.
Thornton scored 15 points and added eight rebounds to spark the Wizards to a 44-38 halftime lead. Boston's uninspired effort led to 35 percent shooting, including a stretch of 8:14 with only two field goals. Garnett and Rasheed Wallace were a combined 1 of 10 from the floor.
- Michael Finley did not dress for Boston.
- Washington has lost five of six.
- Boston won its fourth straight game.