The Celtics improved to NBA's best record to 45-12 and boosted their win streak to a season high while stretching their Eastern Conference lead over second-place Cleveland to eight games.
Jayson Tatum added 19 points, six rebounds and six assists as Boston had six scorers in double figures.
"We've got so many good players on our team," Tatum said. "We always talk about respecting each other's space. It's about understanding it's a rhythm game. It's going to come back to you eventually."
Tatum says the players adopt a long-term approach, keeping in mind the overall goal is an NBA title in June.
"We have a really good team and we understand the important goal, what we're really trying to accomplish, so every single night we're trying to share the love, play the right way and make sure we win more often than not," Tatum said.
Jalen Brunson had game-highs of 34 points and nine assists to lead the Knicks, who fell to 34-23.
Porzingis, who began his NBA career with the Knicks in 2015, sank two 3-pointers and Brown scored five points in a 17-5 third-quarter Boston run that gave the Celtics their biggest lead to that point at 84-71 on the way to a 97-84 lead after three quarters -- the Celtics hitting 68% of their shots from the floor entering the fourth quarter.
Boston kept the Knicks scoreless for five minutes in the heart of the fourth quarter to help seal New York's fate, the Celtics stretching the lead as high as 20 points.
At Minneapolis, the Minnesota Timberwolves seized sole possession of the Western Conference lead with a 101-86 victory over Brooklyn.
Anthony Edwards scored 29 points and Karl-Anthony Towns added 28 to spark the T-Wolves, who improved to 40-17, one-half game ahead of Oklahoma City with the NBA's second-best record.
The Nets sunk to 21-35 with their fourth loss in a row.
Banchero lifts Magic
In the night's only other game, Paolo Banchero's three-point play with 0.1 of a second remaining gave the Orlando Magic a 112-109 victory at Detroit. Banchero sank the game-winning jumper while being fouled and added the free throw for the dramatic triumph.
"It was important," said a tearful Banchero of his final shot. "It was a hard game and I've been sick. I've been feeling terrible. I just give credit to my teammates. They lifted me up the whole game.
"I don't know why I'm crying. It was a hard game. I'm proud of my team."
Banchero's 15 points led eight double-figure scorers for Orlando, which improved to 32-25, level with Indiana for sixth in the East.
The Pistons, led by Cade Cunningham's 26 points, fell to an NBA-worst 8-48 with a fifth consecutive loss.
Franz Wagner's free throw gave Orlando a 109-105 lead with 96 seconds remaining.
Cunningham answered with a jumper and a layup for Detroit, the latter pulling the Pistons level at 109-109 with 12 seconds remaining, setting the stage for Banchero's heroics.
