Everything we thought we knew about the 2022 NBA Finals was blown to pieces in Game 1.

The Boston Celtics were supposed to be the more physically exhausted team after surviving two intense seven-game series against the Miami Heat and Milwaukee Bucks to win the Eastern Conference. The Golden State Warriors were supposed to be aided by the championship experience that came with their three rings, and six NBA Finals appearances in eight years. When push came to shove, great offense was supposed to beat great defense, which was another edge for Golden State.

The Warriors looked like they were well on their way to victory through three quarters in Game 1. Stephen Curry hit six three-pointers in the first period alone. Jayson Tatum couldn’t make a shot all night. Golden State was pounding the Celtics on the offensive glass throughout the game, and had a role player step up with a big-time performance as Otto Porter Jr. shot 4-of-5 from three-point range.

All of that helped the Warriors amass a 12-point lead heading into the fourth quarter. What happened from there was at once one of the great collapses and great comebacks in NBA Finals history.

The Celtics stormed back to beat Golden State, 120-108, to take a 1-0 lead in the NBA Finals. Boston did it by outscoring the Warriors 40-16 in the fourth quarter. The +24 margin in the final frame tied an all-time NBA Finals record.

The Celtics got ridiculously hot from three-point range in the fourth quarter

It’s easy to point to Boston’s hot shooting from behind the arc as the biggest reason they were able to steal Game 1. The Celtics hit 9-of-12 three-pointers in the fourth quarter. They finished 21-of-41 from three-point range — good for 51.2 percent — on the night.

On a night when Tatum shot 3-of-17 overall, Boston’s role players stepped up. Al Horford went 6-of-8 from three. Derrick White went 5-of-8 from three. Marcus Smart went 4-of-7 from three. Jaylen Brown also scored 10 of his 24 points on the night in the fourth quarter.

Warriors coach Steve Kerr immediately brought up Boston’s shooting after the game.

Of course, he wasn’t wrong. But if the Warriors are reducing this collapse to simply hot shooting variance from the other team, they could be in big trouble.

The Celtics’ defense completely shut off the Warriors in the fourth quarter

The Celtics opened the fourth quarter on a 9-0 run to immediately put a big dent in the deficit with Curry on the bench to begin the frame. Curry helped his team get going shortly after checking back in, first assisting on a Klay Thompson three-pointer, then hitting a mid-range shot and a floater himself.

The floater gave the Warriors a 103-100 lead with 6:05 left. Golden State didn’t make another field goal until the 1:09 mark of the fourth quarter.

Boston went on a 17-0 run over that five minute stretch to complete their steal of the game.

The Warriors went 0-for-5 over that stretch. They also had two turnovers, a bizarre offensive foul call on Curry, and an 0-for-2 mark from the foul line. Boston blitzed them on the other end by making some tough shots, but the bigger issue for the Warriors is how flustered their offense looked.

Just look at Boston’s swarming defense on this possession:

The Warriors ran the type of off-ball actions that have defined their offense since their dynasty began, but the Celtics were all over it. Derrick White checks Curry, Thompson, and Poole on that possession. Horford checks Wiggins, doubles Curry, and then sprints to the corner to defend Thompson. All five Celtics defenders are just completely locked in, and the possession ultimately ends with Wiggins missing a contested three.

That’s just one example of how good the Celtics’ defense was during that stretch. Horford had the length to pressure Green out on the perimeter to force a turnover. Brown locked up Thompson on one possession, and allowed Tatum to knock the ball away on a hard dig into the paint. Even Curry couldn’t shake Payton Pritchard on an iso.

Great offense only beats great defense if the offense is actually great. The Warriors’ offense wasn’t. The Celtics defense certainly was.

The Warriors gave up some wide open Celtics looks from three

Of course, the Celtics aren’t going to shoot 51 percent from three on a high volume of attempts every game. But it also must be noted that Golden State was giving up some wide open looks.

Here are a few triples from Boston in the fourth quarter. None of these are contested.

The Golden State defense finished No. 2 in the NBA in the regular season behind the Celtics, but they did give up a lot of looks from three. Warriors opponents took nearly 38 percent of their field goal attempts from three on the season, which ranked No. 21 in the league.

Boston has four or five shooting threats on the floor in every lineup they play. Even if Boston doesn’t have great shooters after Tatum and Brown, they’re competent enough to hit shots, and have been hot throughout the playoffs.

The Warriors can’t just hope the Celtics start missing

This felt like a bizarre quote from Green after Game 1.

The Warriors lost because their offense couldn’t crack Boston’s defense late in the fourth quarter when it mattered. The Warriors lost because their defense yielded way too many wide open looks from three. Poole in particular was an eyesore defensively throughout the night. Porter was somehow -18 despite hitting 80 percent of his threes.

The Warriors had Game 1 in the bag, and they let it slip away. That it happened on a night when Tatum shot 3-of-17 should only make them feel worse. If there’s an area will the Warriors’ championship experience will show up, it would be in their ability to not get too down after that loss — because any other team should be devastated blowing a lead like that so late in the game on your home floor.

The Warriors have real things to address moving forward even beyond hoping Boston misses shots.