Despite holding a 20-point lead midway through the third quarter, the Boston Celtics collapsed down the stretch and saw a Game 1 victory slip through their hands in a 108-105 overtime loss Monday night in TD Garden.

The Celtics missed an NBA playoff record 45 threes, and scored just 16 points in the fourth to drop their first game to New York this season.

While it appeared that most of the Celtics roster experienced some rust after six days off, Jayson Tatum clearly did not.

After Derrick White opened the scoring with a corner three, the opening frame belonged to Tatum, who is coming off of three straight 35-point performances. The forward was assertive early, getting to the charity stripe early for a pair before trading triples with Deuce McBride.

Tatum was really the only source of offense for Boston as he scored eight-straight points, capped off by receiving a touchdown outlet pass from Jalyen Brown for an easy dunk. He kept the offense going by burying a 28-foot stepback triple over Mitchell Robinson.

The Knicks were doing their best to try and keep pace with the Boston superstar as McBride and OG Anunoby hit three-straight threes to take a 20-19 lead.

With just under three minutes remaining in the first, the rest of the Celtics were still having trouble getting going as everyone besides Tatum was shooting a combined 2-14 from the field. That changed once Prtichard stepped into a three to take a four-point lead.

But by the end of the quarter, the Cs only found themselves up one and in a bit of a rock fight with New York. As the second quarter began, the momentum started to shift even further to Boston’s side.

Karl Anthony-Towns did get it going a little bit to kickstart the second with a pair of jumpers, but he quickly picked up his third foul and derailed much of the Knicks offensive attack.