LOS ANGELES >> Hard to believe now, all these wins later, but the Alex Cora Era in Boston began with a loss. A brutal one, in fact.

Opening day at Tropicana Field in late March, none of his late moves worked out as the bullpen blew a big lead in a 6-4 setback.

No fan in New England would admit it now — still, chances are some had already started to wonder whether he was the right guy for the Red Sox.

“It’s baseball,” Cora reassured that afternoon. “We know it’s going to happen. … I guess get it out of the way right away.”

Yep, guess so.

A calming presence in a boiling sports cauldron, Cora capped off one of the greatest runs by a first-year skipper in leading Boston to the World Series championship.

His Cora-nation came tonight, when the Red Sox beat the Los Angeles Dodgers 5-1 in Game 5.

The victory set off celebrations all over.

While throngs of Red Sox fans chanted “Cor-a! Cor-a!” from the seats and so many more reveled across the country, all of Puerto Rico certainly cheered its native son from Caguas.

Cora became the first manager from the island to guide a team to a championship. It came more than a year after Hurricane Maria devastated Puerto Rico — when Cora negotiated his contract last October, he asked the Red Sox to help his people with relief efforts, and the team eagerly pitched in.

Moments after hoisting the championship trophy, Cora made one more request.

“Next thing I’m going to ask ownership is if we can take the trophy to my island,” he said. “That would be great.”

Cora again turned Dodger Stadium into his personal party room. A year ago, he celebrated at the park as Houston’s bench coach after the Astros beat Los Angeles in Game 7. This time, he was front and center when Boston lifted the shiny gold trophy.

“It’s funny, because when they announced it, we were flying to LA last year between the Championship Series and the World Series, and ironic enough we win it here. So it goes full circle,” he said.

Cora became the fifth manager to win the crown in his first season, joining Bob Brenly (Arizona, 2001), Ralph Houk (Yankees, 1961), Eddie Dyer (Cardinals, 1946) and Bucky Harris (Washington Senators, 1924).

Called A.C. by his players, Cora has an unassuming presence. He often wears a gray hoodie in the dugout — the one he wore for Game 5 is headed to the Hall of Fame — and he doesn’t raise his voice. Except to yell at umpires, that is.

Shouting at his own team?

“No, no, I don’t,” he said before Game 5. “I talk to them and I try to stay in tune with them. If I have something to tell them, I just sit with them. Very casual. Very casual.”

“I try to do it that way. It feels right. It feels right,” he said. “I never had a manager that was like rah, rah, screaming at guys. They always had good conversations, and I learned from them and that’s what I’m trying to do.”

The result, said shortstop Xander Bogaerts, is Cora’s influence is “all positive, no negative stuff going on.”

His dugout demeanor is boosted by a combination of analytical aptitude and people approach.

“Coralytics” is what it’s called by his agent, Scott Boras.

Cora was hired after John Farrell, who led the Red Sox to the 2013 title, was fired following two straight early exits in the AL playoffs.

“Alex was the manager that fit for us. He was really good in so many ways,” Red Sox President of Baseball Operations Dave Dombrowski said before Game 5. “He knew Boston. I think he excels in dealing with the media, which in Boston is a bigger job than some other places. It can be cumbersome for a lot of people, and I’m not saying it’s not for him at times, but it’s part of the process and he handles it easily.”

Cora was chosen over about a half-dozen candidates that included former managers Brad Ausmus and Ron Gardenhire.

“It was a clear-cut choice that he was our guy,” Dombrowski said.

After the opening loss, Boston won 17 of its next 18 games and was on its way.

Cora steered the Red Sox to a team-record 108 wins in the regular season, then Boston topped the 100-win Yankees and Astros in the playoffs. Along the way, it seemed Cora could do no wrong.

Brock Holt hit for the first postseason cycle when Cora gave him his only start of the Division Series against New York. Cora masterfully managed a bullpen that many questioned before October, then avoided burning it out by leaning on hard-throwing starter Nathan Eovaldi in key spots. And Cora helped coax a breakout postseason from World Series Game 5 winner David Price.

“A.C. told us from the first day in spring training we could do it,” AL MVP favorite Mookie Betts said. “We believed in ourselves, we believed in him and we went out and executed.”

The clinching win at Houston came on the day Cora turned 43, and his players sang happy birthday to him in the clubhouse.

“More than anything, he’s just brought consistency,” ace Chris Sale recently said. “He’s the same guy in the first inning as he is in the ninth inning of a 10-1 ballgame or 3-3 ballgame. I think that’s the overall thing as players that we take from him.

“Ninth inning, bases loaded, one out of a one-run ballgame, and he’s sitting there eating seeds, doing the same thing as a 10-1 ballgame in the fourth inning. And I think that goes very well with us as players, when if he’s not panicking, why should we?” Sale said.

Cora grew up playing ball with his older brother, Joey, a former big league infielder. Alex spent 14 years in the majors, batting .243 as an infielder with six teams.

He got to the plate one time in Boston’s sweep of the 2007 World Series, putting down a sacrifice bunt for a team led by David Ortiz, Dustin Pedroia and Manny Ramirez.

“Offensively, we did a lot of good things. And then the bench, it was amazing, they had the best utility guy in the bigs in 2007,” Cora said with a playful grin tonight. “That guy was great.”

With the season over, Cora can enjoy spending more time with his twin 15-month-old boys and older daughter. He can do that free from any criticism that comes with such a high-pressure job, too, although he doesn’t stress over it.

“I really don’t care if they second-guess me. I prepare. We prepare as a group, and you make decisions,” he said after Game 1. “And honestly when I’m done here, I shower, I get in that car, I might get a text and say, “Go to the pharmacy and get some diapers for the kids.”