The Celts’ Paul Pierce throws down a resounding dunk in front of the Nets’ Brook Lopez during the first quarter last night.

AP / Elise Amendola

BOSTON — It’s OK to exhale.

The Boston Celtics have officially snapped out of their funk.

Last night, in front of a sellout crowd of 18,624 at the TD Banknorth Garden, the Celtics (32-9) captured their third straight victory with a decisive 118-86 triumph over the New Jersey Nets (19-20) in a battle between the top two teams in the Atlantic Division.

“This is great, great!” Boston coach Doc Rivers said. “We obviously needed it.”

It was a total team effort. Six Celtics scored in double figures, and none of the starters played in the fourth quarter because the game was so in hand.

In fact, all 11 Celtics who played scored at least two points.

“I think we started geting into a little rhythm like what we’ve been doing throughout most of the year,” Boston captain Paul Pierce said.

Paul Pierce nearly single-handedly outscored the Nets in the third quarter, when he recorded 18 of his team-high 22 points. He connected on all five of his 3-point shots in the quarter without a miss.

“It wasn’t me just trying to come out and get it going,” Pierce said. “I just took advantage of the ball movement. We swung the ball and I was wide open. I stayed aggressive.”

“He had great looks,” Rivers said.

Kevin Garnett scored 20 points and pulled down 9 rebounds, while Rajon Rondo had 11 points, 12 assists and 7 rebounds.

“When it comes to throwing lobs, he is one of the best I’ve played with,” Garnett said of Rondo. “He puts the ball right where you need it.”

Brian Scalabrine, who started in place of the injured Kendrick Perkins (left shoulder strain), had nine points and four rebounds. The Celtics are now 3-0 with Scalabrine in the starting lineup.

The Celtics were impressive on both ends of the floor. They knocked down 56.4 percent of their shots (44-for-78) and they limited New Jersey to 38.8-percent shooting (26-for-67). The Celtics also scored 27 points on 20 forced turnovers.

“When you look at our games, when we play, we always measure ourselves on how we do defensively,” Pierce said. “Tonight, I thought we did a great job throughout the game.”

As good as the starters played, the bench was the reason why the Celtics broke open the game.

Boston’s second unit of Glen Davis (12 points), Eddie House (10 points), Leon Powe (5 points, 8 rebounds) and Gabe Pruitt (9 points, 4 assists), along with Pierce, helped break a close game open.

They controlled the pace from the end of the first quarter through the midway point of the second quarter, paving the way for Boston’s starters to go on cruise control.

Davis heaved up a desperation 3-pointer, the first of his career, at the end of the first quarter, extending Boston’s lead to 30-23. That sparked a 14-2 run by the second unit, giving Boston a 41-25 cushion. Davis capped off the surge with a layup and a free throw.

As good as they were offensively, Boston’s backups were just as good defensively. They forced the Nets to miss their first 10 shots in the second quarter, which set the tone for the rest of the game.

“They are a great defensive team,” New Jersey forward Ryan Anderson said of the Celts. “They definitely altered our shots, and we weren’t shooting the ball like we normally do. We weren’t moving the ball around. They were denying our wings. They were getting into us. They controlled the tempo, defensively and offensively.”

New Jersey was able to slash Boston’s lead to 51-41 by halftime, but the Celtics opened up the third quarter with a 14-3 run and cruised from there.

Because of the rout, rookie Bill Walker (career-high 6 points) was able to see his first action with the Celtics since Nov. 9, and little used center Patrick O’Bryant (2 points) also got into the game.

“Well, obviously they played extremely well,” New Jersey coach Lawrence Frank said. “They kicked us real good. It was a 10-point game at half, and in the third quarter they just knocked us down. We gave up a high volume of layups and our turnover-to-assist ratio was very disappointing.”

Devin Harris (17 points), Brook Lopez (13 points, 8 rebounds) and Anderson (13 points) led New Jersey.

roblee@projo.com