BOSTON -- Center Brook Lopez scored nine of his season-high 30 points during a decisive fourth quarter and Joe Johnson added 20 points in the Brooklyn Nets' 100-97 victory over the Boston Celtics at TD Garden on Saturday.

The Nets (10-23) won for the second time in the past five games and overcame the loss of guard Jarrett Jack to a right knee sprain in the third quarter.

"We definitely took steps in the right direction," Lopez said. "There were some miscues but we kept fighting. We stuck together and pulled through."

Lopez's dunk with 26.9 seconds left put the Nets ahead 100-95 after a 5-0 Celtics' run. Boston missed a pair of 3-point attempts before Evan Turner's layup cut the Brooklyn lead to 100-97 with 11.1 seconds remaining. The Nets turned the ball over but Jonas Jerebko missed a 3-pointer from the corner just before the final buzzer.

"It was a nice win. We played really well," Nets coach Lionel Hollins said. "We played well enough to win that game down the stretch. We made some mental mistakes, physical mistakes and allowed them to get all the way back and have a chance to make a three to tie the game up. But they didn't and we won the game. And we're thankful for that."

The Celtics (18-15) have lost two in a row after winning the previous four. Guard Isaiah Thomas led Boston with 24 points and Celtics guard Avery Bradley left the game in the second quarter with a bruised hip and did not return.

The Celtics' recent defeats were to teams (the seven-win Los Angeles Lakers and Nets) who are far from playoff contenders.

"Well I said after the Knicks game (a win on Dec. 27), I thought that we had a lot of holes, especially offensively at the time," Celtics coach Brad Stevens said. "I feel like we've just been really, really passive, to be candid. I've got to reassess things. I've got to do a better job. I've got to hold guys accountable at a better level. We're not playing as well as we think we are. So we've got to be better."

The loss was doubly deflating for the Celtics, who hold the Nets' first-round pick in the 2016 NBA Draft. Boston and Brooklyn meet against Monday at Barclays Center.

The Celtics trailed by 10 points entering the final quarter but a 12-2 run tied the score at 83. The Nets responded with Lopez scoring seven points during a 9-2 run for a 92-85 lead.

A basket by Joe Johnson with 2:22 remaining put Brooklyn ahead 98-90.

"We just waited too late to really fight," Celtics forward Jae Crowder said.

The Nets opened the game with 6-0 run that forced the Celtics to call a full time out 2:02 into the game. Out of the timeout, the Nets extended to an 8-0 lead on Lopez's basket before Bradley got the Celtics on the board at the 9:07 mark.

The Celtics pulled within 11-10 before Lopez, who had 10 points in the quarter, had a three-point play to extend Nets' lead to 14-10 at 7:09. Boston responded with a 5-0 run capped by Thomas' 3-point basket at 6:21 that gave the Celtics their first lead of the game.

Boston led by as many as four in the quarter and led 29-27 when Brooklyn's Bojan Bogdanovic hit a basket and Jack sank a pair of free throws to give the Nets at 31-29 lead after the first quarter.

Brooklyn used a 9-2 run during the second quarter to open up a 48-40 lead capped by three free throws by Wayne Ellington at 5:56. The Celtics answered with a 9-0 run and took a 49-48 lead on David Lee's basket with 2:18 left.

The Nets overcame a field-goal drought of 5:56 with some proficient free-throw shooting and took a 56-55 lead into the half. Lopez led the Nets with 16 points in the first half; Thomas led the Celtics with 13.

Tempers flared early in the second half when Jared Sullinger pulled down Lopez on a layup attempt at 9:56 of the third quarter. The officials reviewed the play and the foul was called a flagrant 1. Crowder and Jack were assessed technical fouls for the jawing that took place after the foul.

The Nets opened the third quarter with an 11-3 run. They outscored the Celtics 25-16 in the period and led by as many as 13 points. They took an 81-71 lead into the fourth quarter.

The Celtics never led in the second half.

"Basically in comes down to we play down to what records say," Celtics guard Marcus Smart said. "In this league you can't do that. We start out the game real, real sluggish and we let teams get comfortable and they make us pay for it."

NOTES: The Boston Celtics assigned F Jordan Mickey and G Terry Rozier to the Maine Red Claws of the NBA Developmental League. Mickey, a rookie from LSU, has averaged 2.3 points, 1.0 rebounds and 0.3 assists per game in six minutes played over three games. He last played Dec. 21. Coach Brad Stevens said Mickey is only being removed from the NBA roster because of a logjam at forward. "He's closer to ready than ever before," Stevens told the media before the game against the Brooklyn Nets on Saturday. ... Brooklyn rookie F Chris McCullough was cleared for contact Friday and took part in a contact practice. The Syracuse product has not played this season and he's recovering from a knee injury. ... Celtics G R.J. Hunter missed the game with a shoulder injury. He was injured in the fourth quarter of a game he played with the Red Claws earlier this week. He scored 28 points in that game. Stevens said he believes the injury will be "short-term." ... The Celtics and Nets will meet again Monday in the second half of their home-and-home series. The last time Boston visited Brooklyn, the Nets won 111-101.