Jalen Brunson and OG Anunoby each scored 29 points before Mikal Bridges stole the ball from Jaylen Brown with a second left in overtime as the New York Knicks stunned the Boston Celtics 108-105 in Game 1 of their Eastern Conference semifinals series on Monday night.

Karl Anthony-Towns added 14 points and 13 rebounds for New York, which lost all four games against its longtime rival during the regular season and trailed by 20 points in the second half of this game.

Jayson Tatum and Brown both had 23 points for the defending champion Celtics, who had an NBA playoff-record 45 missed 3-pointers to blow a game they appeared to have in control. Derrick White added 19 points and 11 rebounds.

Jrue Holiday returned to the starting lineup after a strained right hamstring caused him to miss the final three games of Boston’s first-round series with Orlando. He finished with 16 points in 39 minutes, but center Kristaps Porzingis played only 13 minutes and didn’t return after halftime because of an illness.

The Knicks struck first in OT, taking a 106-100 edge via a three-point play by Anunoby, followed by 3-pointer by Bridges.

Brown connected on a 3-pointer from the wing with just over a minute left — his only make in 10 attempts behind the arc — to cut it to 108-105.

It stayed that way when Josh Hart misfired on a deep 3. Tatum missed a jumper, but the Celtics were able to retrieve the rebound. After a foul on Towns, Boston called timeout with 3 seconds showing on the clock.

But Bridges ripped the inbounds pass away from Brown to preserve the win.

The Celtics finished 15 for 60 on 3-pointers.

A wild end to regulation set up overtime.

New York cut what had been a 16-point halftime deficit to 84-75 entering the final period, thanks to a 20-9 run to end the third.

The Knicks kept it going, scoring the first eight points of the fourth quarter. They eventually tied it at 86 on a steal and dunk by Anunoby.

Three ties and three lead changes later, New York led 97-95 when the Celtics pushed the ball ahead and swung it to White for a corner 3-pointer to put Boston back in front with 2:15 left.

A 3 by Anunoby put New York in front by two, but it was answered on the other end by Holiday’s layup to tie it again. Anunoby missed a 17-foot fadeaway and White grabbed the rebound and Boston was able to call timeout with 28 seconds remaining.

Boston ran the clock down and got it Tatum, who missed a 3 from the top of the key, and New York rebounded with 5.5 seconds left.

Brunson got a give-and-go pass from Towns but missed a short layup that was rebounded by Boston. The Celtics called timeout with 0.6 seconds remaining. But Tatum missed a lunging jumper at the buzzer.