Celtics forward Jayson Tatum scored just 12 points on Thursday night, but he had 13 assists in Boston’s 120-108 win over the Golden State Warriors in Game 1 of the NBA Finals in San Francisco. AP Photo/Jed Jacobsohn

The Boston Celtics basically inflicted a worst-case, nightmare scenario on the Golden State Warriors in Game 1 of the NBA Finals.

Jayson Tatum scored 12 points. He shot 3-for-17, and couldn’t hit a 3 to save his life. He was a complete non-factor shooting the basketball, as the Warriors basically kept the Celtics’ star from matching scores with Steph Curry (34 points).

And yet, much to the Warriors dismay, it meant nothing, as the Celtics won going away in front of Golden State’s home crowd at the Chase Center.

Talk about having to go back to the drawing board, the Warriors basically had no answer for everyone else, as the Celtics enjoyed a 120-108 win in the opener.

Thanks in part to a spectacular fourth quarter led by Jaylen Brown, who set the tone by attacking the basket, along with Al Horford (26 points), Derrick White (21 points) and Marcus Smart (18 points), who threw up one dagger 3 after another, the Celtics were able to start off in the driver’s seat of this seven-game series.

If that wasn’t bad enough, it’s bound to get worse for the Warriors.

Tatum isn’t going to be cold shooting the entire series, no matter how well they defend him. And if everyone else continues to make shots as they did during Game 1 largely from Tatum feeds, the Warriors are going to have a tough time preventing the Celtics from capturing Banner 18.

That’s how good of a first impression the Celtics made in the come-from-behind win, erasing a 12-point fourth-quarter deficit with a 40-16 run.

“You give up 40 in the fourth and the other team makes 21 3s, it’s going to be tough to win,” Warriors head coach Steve Kerr said following the loss.

It’s going to be tough for the Warriors to win if Tatum also joins the crowd, whether it’s in Game 2 or 3 or 4, or all of the above. And it will remain tough even if Tatum is kept at bay, and the Celtics still have three players scoring 20 or more points, as they did in Game 1.

Tatum, who was awarded the inaugural Larry Bird Trophy as the MVP of the Eastern Conference Finals, made just one 3-pointer the entire game. He did not score a single point in the fourth quarter.

No matter, Horford (6-for-8 from distance), Smart (4-for-7) and White (5-for-8) picked up the slack with 15 of the team’s 21 3-pointers.

Tatum’s reaction to the Celtics humbling the Warriors with a crushing 40-point fourth?

“Ecstatic, right? 40 points in the fourth quarter? JB played big. Al, Payton (Pritchard), D-White. Those guys made big shots, timely shots as well. And we won, right?” he said. “I had a bad shooting night. I just tried to impact the game in other ways. We’re in the championship. We’re in the Finals. All I was worried about was trying to get a win, and we did. That’s all that matters at this point.

“So I don’t expect to shoot that bad again. But if it means we keep winning, I’ll take it.”

And it’s not that Tatum’s bad night shooting completely eliminated him from making an impact. His career-high 13 assists in itself was “a game-changer” as Pritchard described following the game.

Tatum consistently found the open man with the Warriors essentially tying him up with a box-and-one type defense, especially early in the game.

“We’ve talked about it throughout the year and I’ve talked to him at length about impacting the game when he’s not having his best offensive night. So he did that tonight,” Celtics head coach Ime Udoka said of Tatum. “Obviously going 3-of-17, that’s usually not going to happen.

“What he did well and did early was get others involved. (He had) 7-of-9 assists pretty early in the game, finished with 13, and the shots not falling, he still attracts a good amount of attention, made the right plays …

“When they went a box-and-one on him to try to take him out,” Udoka went on, “it made it tough at times, but that’s why we’re a team. We don’t rely on one guy. You saw others step up tonight.”

The Warriors basically couldn’t contain the rest, while the Celtics finally locked in on defense late in the game.

Brown was truly the catalyst of the fourth-quarter barrage. He started the early 7-0 run with a step-back jumper, a 3-point bomb, while dishing off to Rob Williams for a monster jam.

“He had a great start to the fourth quarter,” Udoka said of Brown, who finished with 24 points. “With JT struggling a little bit, we went to him more. He was extremely aggressive getting downhill. Got the bigs switching on him and got the shots that he wanted.”

And, he calmly drained them.

If Tatum is off, Brown has typically been pretty good at putting points up, and taking over. After the game, he called it a collective effort.

“We’re battle-tested. We’ve been through a lot,” said Brown. “We’ve been through a lot of experiences, a lot of losses. We know what it takes to win.”

Indeed, they do.

Curry said some Celtics had “career nights” shooting the ball, and that was the difference in the game.

Well, that’s typically how the Celtics have been rolling during the playoffs, along with their run toward the postseason.
Someone else has managed to step up and deliver whether Tatum, Brown, Horford or whoever had a rough shooting night. In this case, it was a collection of Celtics who took over in the fourth quarter with Tatum acting more as a facilitator.

Said Warriors forward Draymond Green: “You’ve got to give them credit. They made the shots when they needed to make them.”

They made them, even if Tatum didn’t and was held to a dozen points. And that proved a killer for the Warriors.