BOSTON — So, this was the plan all along, wasn’t it? A dynamic young manager, inspiring his baseball team to a fast, impressive start. Spinning scoreboards that resembled pinball machines more than ballparks. The occasional lights-out performance from a starting pitcher. Engaged fans.

Just the way the Yankees drew it up.

Only these are the Bizarro Yankees, also known as the Boston Red Sox, also known as the best team in the American League and the A.L. East (by 2½ games) and, specifically, the A.L. East, Heavyweight Division (by 4½ games). The Bizarro Yankees splattered the Real Yankees again Thursday night, this time by a 6-3 score that felt like a whole lot more until the Yanks managed to make things a little interesting in the ninth.

“It was a good series for us,” said Red Sox manager Alex Cora, whose first fortnight as a manager has gone just a little bit smoother than Aaron Boone’s. “Winning two out of three is always the goal. We’re happy with that.”

It was sort of easy to forget who the two-time champions of the East were, because the Yankees clearly won the offseason. It was sort of easy to forget that the Sox had won 93 games in 2016, and 93 more a year ago, and still had most of the key players back and ready to add another flag to the side of Fenway Park.

And on Opening Day, at least, it felt like all was falling easily according to the offseason script. The Yankees pounded the Blue Jays and Giancarlo Stanton hit a couple of home runs and looked like a cross between Babe Ruth and Lou Gehrig; Luis Severino threw six shutout innings and looked like a cross between the Young Gooden and the Young Gibson.

Meanwhile, in St. Petersburg, the Sox were blowing a big lead to the Rays, a team that’s barely trying to win.

For 24 hours, anyway, everything seemed perfectly in order.

In the 14 days since, things have turned upside-down. The Sox recovered on Day 2, didn’t lose for almost two full weeks, winning from way ahead and winning from way behind and throwing a 14-1 haymaker at the Yankees in the first of 19 meetings between the rivals on Tuesday.

The Yankees? Putting it kindly, Stanton is no longer on a 324-homer pace. The bullpen, which was their crown jewel, has stumbled. Even Severino, who looked so untouchable in his first two starts, was bombarded Tuesday night at Fenway, a reminder that even the most gifted baseball prodigies are due a humbling or three along the way.

They won Game 2 of the series, but only after Masahiro Tanaka tried mightily to blow an 8-1 lead, settling for a 10-7 win on a night when old tempers flared and ancient flames were rekindled. But they followed that Thursday night with a loss that might’ve been even more troubling than Tuesday, because there was no life to them, little energy, little fight against Rick Porcello — loser of 17 games last year — who no-hit them for six innings.

And Fenway Park noticed.

“It was so great in here,” Cora said. “It really was.”

It’s funny; so much has changed in Boston in the decade and change since the Sox and the Yankees were annual steel-cage combatants. The Sox used to be the unchallenged kings of New England, despite a championship drought that predated Prohibition.

When they finally won it all, in 2004, it was impossible to believe a city could ever be more deeply infatuated with a team. But a funny thing has happened: Even as the Sox added two more titles, they were challenged by the Celtics and challenged by the Bruins and, according to most Olde Towne observers, have been lapped by the Patriots, the new masters of Massachusetts and the precincts beyond.

Still, it was hard to decipher that at Fenway the past few days, where they resurrected the ever-useful standby, “YANN-KEES SUCK!,” where on Thursday the 36,341 sang “Sweet Caroline” like it was 2003 all over again.

Now, this is April, and still absurdly early. Plenty can change in a month, let alone the 5½ that remain in the season. The Yankees are too good to look this bad for too long. By the time everyone reconvenes at Yankee Stadium the second week of May, we could all be singing a different tune. All fair.

For now, for the moment, for the Sox, the good times never looked so good.

(So good. So good. So good.)