It didn’t matter who guarded him or how Brooklyn’s stars countered — Jayson Tatum was too much for the Nets in Game 3.

What Jayson Tatum faced Friday night going against Kevin Durant, James Harden and Kyrie Irving – the Boston Celtics’ lone star vs. Brooklyn’s veritable constellation – was pre-imagined way back in 1968, in the brilliant opening scene of Sergio Leone’s spaghetti Western “Once Upon a Time in the West.”

It’s a sequence best enjoyed in its entirety, but for our purposes, we’ll – spoiler alert! – cut to the end. Charles Bronson steps off a train, only to find three salty dudes waiting for him on the railroad platform. One of them, liking the odds, snickers and says to Bronson, “Looks like we’re shy one horse.”

Bronson just squints harder and shakes his head. “You brought two too many.”

At which point he outguns all three.

Kind of how Tatum outplayed the Nets’ Big Three in Game 3 to boost Boston back into its Eastern Conference first-round series. The young Celtics star stared down Durant, Harden and Irving and hung 50 points on Brooklyn to send them all into a more intriguing Game 4 Sunday (7 ET, TNT).

Now don’t get it twisted: Tatum didn’t outscore the three by himself. Brooklyn’s trio combined for 96 of its team’s 119. But against a pair of former Kia Most Valuable Players as well as seven scoring titles and 27 All-Star selections for the bunch, Tatum was the best player on the court.

As good as Celtics and NBA fans have seen in a while.

Tatum, a two-time All-Star, became the third-youngest player in NBA playoff history to score at least 50 points, with only Rick Barry (55 at age 23 years, 21 days) and Michael Jordan (63 at 23, years, 62 days) doing it younger than Tatum by mere weeks (23 years, 86 days).

He also became only the sixth Boston player to score 50 or more in a playoff game, joining legends such as John Havlicek (54), Sam Jones (51), Ray Allen (51) and Bob Cousy (50). The last Celtics scorer to do it before Friday was Isaiah Thomas, who had 53 against Washington in 2017.

As a matter of fact, Tatum scored 50 against the Wizards himself 10 days earlier, rising to the occasion in his “favorite arena” to keep Boston out of harm’s way in the No. 7 vs. No. 8 play-in game.

What he and his teammates avoided this time was even more ominous. Dropping to 0-3 in an NBA best-of-seven series is the equivalent of circling the drain, with a 0% chance of surviving according to league history. Teams in that predicament have a 0-140 record, to be exact.

Now the Celtics have a chance to pull even, with a home crowd of about 5,000 that was helpful Friday swelling to 17,000 for Game 4 Sunday as local virus restrictions loosen this weekend.

It’s not fair to expect Tatum to be as good again in 48 hours, but the people in the stands and his teammates on the floor will be hoping.

“I told JT great players run it back two nights in a row,” Celtics center Tristan Thompson said after grinding his way inside to 19 points and 13 rebounds, nine on the offensive end. “The greats know when certain situations are on the line, and it’s time to step up the performance. JT knows that.”

Following up a 50-point game won’t be easy, but it probably will be more fun than how Tatum came in after his dreary Game 2. He scored just nine points on 3-of-12 shooting in that 22-point drubbing, logging only 21 minutes when Durant ended his night with a poke to Tatum’s right eye.

He thus added this to his list of achievements Friday: First player in playoff history to score 50 after scoring in single digits in the previous game.

Boston coach Brad Stevens was especially pleased with Tatum’s knack for reading the game, knowing instinctively when to make plays for teammates vs. looking for his shot.

“He’s getting really good at it,” Stevens said. “He’s so advanced for 23 years old. I’ve said the word ‘special’ – I don’t say that very often, obviously. He just has a unique ability to score the ball. To slither through seams. To find angles to score. But also he’s got the vision to make every right move. He was super tonight. But he’s been like that a lot this year.”

Reading the game was crucial, too. Things looked bleak when Boston fell behind 19-4 in the first few minutes, yet the Celtics went on a 29-13 run to close the quarter with a 33-32 lead. Tatum scored 13 points during that run.

Midway through the third quarter, what had been a 10-point lead for the Celtics fizzled into a 73-72 deficit. In a little more than five minutes, they were in front by 17, 96-79, with Tatum scoring 11 in that 24-6 tear.

And near the end, after missing his final 3-point attempt and watching Irving with a pair of free throws inch the Nets to within 120-115, Tatum stepped up on last time. Defended by Durant, he rocked the Brooklyn star a step backward, then hoisted a 22-footer over his outstretched arm. It got Boston’s lead back into three-possession territory with 41.8 seconds left.

“Just make a play,” Tatum said of that bucket. “Obviously I knew I had it going. But trying to see where the help was – somebody was coming . In those situations, just make the right play.”

Harden (41 points) and Durant (39) were pretty special too. And while controversial former Celtics guard Irving didn’t have a triumphant return to TD Garden either individually or collectively, he did chip in 16 points on 6-of-17 shooting.

That was better than his counterpart Kemba Walker, who generally is considered Boston’s third star when he isn’t missing 11 of his 14 shots and turning over the ball five times compared to three assists. As for their team’s second star, Jaylen Brown, his season ended in early May with a torn wrist ligament.

So Tatum took on Durant, Harden and Irving one against three, and got what he and Boston needed when role guys such as Thompson, Marcus Smart (23 points) and Romeo Langford off the bench (6 points, 6 rebounds, plus-21) followed his lead.

Now the Celtics get the chance to drop another spoiler alert on the Nets.