The Celtics did what no other NBA team has done this season.

They beat the Golden State Warriors at home.

The Warriors had not lost a regular season home game in over 14 months, winning 54 straight at Oracle Arena. The Celtics came into the game on the second night of a tough back-to-back. Jae Crowder did not play after having gone 34 tough minutes the night before in Portland in his first game back from a high ankle sprain. But the gritty Celtics still managed to put a bump in the Warriors road to history with a dramatic 109-106 win.

How did the Celtics do it? It all starts with the defense. In Marcus Smart and Avery Bradley, the Celtics have two of the best perimeter defenders in the NBA. They held the splash brothers — Steph Curry and Klay Thompson — to a combined 15-of-35 from the field.

The last two nights the Celtics’ defense harassed two of the great shooters in the league, Damian Lillard and Steph Curry, to shoot a combined 12-for-35. Now that’s great defense.

This was not the case of the Warriors having a bad night. This was a scrappy Celtics team playing at a high level. Jared Sullinger was a huge factor inside as he finished with 20 points and 12 rebounds. He and Amir Johnson did a great job on the defensive boards holding the Warriors to one shot on offense for most of the fourth quarter.

4/1 Postgame Report: Celtics Upset Warriors

In their second night of a back to back the Boston Celtics do the unthinkable and defeat the Warriors at home.

Posted by Boston Celtics on Saturday, April 2, 2016

Evan Turner hit big shot after big shot down the stretch as he filled the box score up with 21 points, five assists, and five rebounds. Turner is a free agent this summer and the former No. 2 draft pick has found a home here with the Celtics and Brad Stevens. Signing Turner is a summer must for Danny Ainge.

And speaking of Brad Stevens, he was masterful in the fourth quarter. The Celtics had a ten point lead with 6:18 left. The Warriors Leandro Barbosa hit a three cutting the lead to seven. Stevens called an immediate timeout to settle his team down for the stretch run. The Warriors cut the lead to two point with 1:29 left. Stevens called another timeout and put Amir Johnson in the game for Jared Sullinger. Johnson came up with a key steal with 23 seconds left and the Celtics up by two.

In case you've forgotten, Isaiah Thomas was cold-blooded long before he arrived in Boston.

Posted by The Players' Tribune on Saturday, April 2, 2016

And I haven’t even mentioned Isaiah Thomas yet. The Celtics spark plug loves playing against the best the NBA has to offer. Thomas led the Celtics in scoring with 22 points and added six assists.

In the long 82 game NBA season, there are only a few really memorable games. The Celtics have had two of these against what may be the best team in NBA history. They lost a dramatic double overtime game to the Warriors in December at TD Garden and then became the only team to beat the Warriors at home this season.

Here’s hoping Kevin Durant was watching this one.