This is why the Knicks traded for Karl-Anthony Towns.

With New York’s season hanging by a thread — down 10 on the road entering the fourth quarter in a series it already trailed 0-2 — Towns took over and scored 20 the rest of the way.

Combine that with the best New York defensive performance of these playoffs — their scrambling and ability to peel-switch off Haliburton to stay in front of him but cover pick-and-pop shooters has improved dramatically — and the improbable happened.

New York came back to take Game 3 106-100 on the road. Indiana still leads the series 2-1 but Game 4 on Tuesday night suddenly becomes a swing game in the Eastern Conference Finals.

This was a game where Knicks coach Tom Thibodeau tried everything.

Thibodeau made his big move before the game, starting Mitchell Robinson next to Karl-Anthony Towns and sending Josh Hart to the bench — and it worked out of the gate. Indiana shot 2-of-8 to open the game (although some of that was just missed open looks) and they had just one assist early, allowing New York to get out to a 15-10 lead.

Then Hart was subbed in for Towns, the Pacers hit back-to-back 3-pointers to retake the lead, and it was on.

Indiana dominated most of the rest of the first half.

A stretch in the second quarter summed up this game because both teams ran everything through or at Jalen Brunson. The Knicks had to initiate their offense with Brunson, not having another quality perimeter shot creator has been an issue, and it caught up with the Knicks here. On the other end, Indiana has targeted Brunson in pick-and-rolls and on switches relentlessly all series, but they were especially focused in this game and it spiraled into that second-quarter run where Indiana stretched its lead out to 20.

The other thing Tibodeau did was finally trust his bench (foul trouble for Towns and Brunson played into that). The Knicks came back with 16-4 run into the fourth quarter sparked by bench players — Miles “Duece” McBride and the previously unseen this series Delon Wright and Landry Shamet. Those guys brought the two-way play New York had been lacking.

Towns finished with 24 points and 15 rebounds, saving the Knicks’ season. Brunson finished with 23 points and despite a rough night came up clutch when it mattered.

Indiana shot 20% from 3 as a team (5-of-25) and got 20 points from Tyrese Haliburton and 19 from Myles Turner. That said, the Pacers struggled to create good looks when it mattered against a desperate Knicks team, and they will need to do that Tuesday to take control of this series.