With the win, the Celtics head into the All-Star break with the best record in the Eastern Conference.
Pierce, who was 0 for 10 and had one point in Sunday's victory over the Miami Heat, scored seven points during a 16-0 run late in the fourth quarter as the Celtics turned a one-point deficit into a blowout.
Kevin Garnett scored 14 points with 10 rebounds for Boston.
Ray Allen scored 12 points and Rajon Rondo — Boston's fourth All-Star — had seven points and eight assists. Allen sank a 3-pointer with 5:58 left in the fourth quarter to give the Celtics an 80-78 lead and start them on a 16-0 run.
Pierce, who missed his first four 3-point attempts, sank one from the top of the circle with 3:56 left to give Boston an 85-78 lead. That gave him 1,542 in his career, tying Tim Hardaway for 12th on the NBA's career list a mere 1,022 behind Allen, who broke Reggie Miller's NBA record last week.
Pierce and Allen will represent the Celtics in the NBA's 3-point contest during All-Star weekend in Los Angeles.
The Nets did not score again until Derrick Favors hit a pair of free throws with 55 seconds left.
The Celtics had lost three of their last five games, but they head into the break percentage points ahead of LeBron James, Dwyane Wade and Miami in the East. After losing to the Los Angeles Lakers on Thursday in an NBA finals rematch, Boston beat the Heat on Sunday to clinch the season-series against them.
The Celtics scored the first eight points of the game and led by 15 in the first quarter. It was a seven-point game with 3½ minutes left in the half when Morrow hit a 3-pointer as the Nets outscored Boston 10-3 heading into the break to tie the game at 46.
New Jersey then made the first four baskets of the second half — two by Lopez, two by Harris — to take its first lead of the game and eventually open a nine-point lead. But it was all Celtics in the fourth quarter.
Notes: Nets F Travis Outlaw went down after collision with Luke Harangody in the fourth quarter, but he was able to walk off on his own. ... New Jersey coach Avery Johnson called a timeout just 29 seconds into the game after the Celtics scored on their opening possession. ... Ray Allen and Paul Pierce, who will represent the Celtics in the 3-point contest at the All-Star game, missed their first five shots from beyond the arc and finished 2 for 7. ... The Nets won 104-96 in Boston on Feb. 27 last year for one of their four road wins in the season. They have won four already this season. ... New Jersey is 0-9 vs. the Atlantic Division.