All across the long, hot summer lay the promise that a night like this was awaiting the Yankees on the other side, in autumn. Every night, Aaron Boone would fill out a lineup card authored as much by imagination as ingenuity, fresh names spackled in there, fill-ins, irregulars, stand-ins.

There was a charm to that, sure, because the Yankees started winning a couple of weeks into the season, no matter how Boone crafted the batting order, no matter if the names were as unfamiliar to him as if he were scouring an out-of-town phone book. They kept winning, and winning, and that became the mantra of a year that saw 30 different players make a total of 39 trips to the injured list: next man up, and all that.

Still, always, there was the promise of this: the whole varsity, together.

And this: A lineup, 1-through-9, containing the nine best players on the team, the kind of lineup that, during spring training back in Tampa, Boone figured he’d be able to use 100, 110 times this year. Maybe he couldn’t know then that Gio Urshela would turn out to be an able replacement — an upgrade, even — for Miguel Andujar at third. He couldn’t know in April that Edwin Encarnacion would become part of the party; that would have been a nice surprise.

Finally, on Friday, Boone got to write the first nine names on his depth chart. And, goodness, that couldn’t have worked out better.

The final was 10-4 in Game 1 of the American League Division Series, the Yankees not so much beating the Twins as grinding them up, waiting the out, at last overwhelming them, wave after wave, batter after batter, inning after inning. The Twins raced to a 2-0 lead that felt as temporary as a Kardashian marriage. And it was.

“When we are all together,” Brett Gardner said, “that’s a very deep lineup.”

The Yankees sped by, splattering the Twins with so much of their dust that by the end they were so dusty, they all resembled Pig Pen, Charlie Brown’s old friend. October was already going to be plenty interesting around here. Now it feels as if the Yankees are about to take a step even higher than we thought. For once, they feel complete.

For once, they feel whole.

“It’s remarkable,” Boone said. “I think we’ve had some good fortune here this last month, for the most part, I think Giancarlo [Stanton] being able to get back in the way he has, it’s gone pretty well. Edwin having the questions going into this week, would he be able to get over that final hump and feel comfortable that he is?

“So it’s definitely good to go in with pretty much a loaded barrel, you know?”

Loaded? Once the Yankees took a few innings to acclimate themselves to the postseason, it felt as if they could do whatever they wanted. DJ LeMahieu had three hits and four RBIs, of course, because that what he has done all year, the one reliable anchor in a lagoon of uncertainty. Gleyber Torres untied the game for the last time, because he has quickly become the Yankee who opponents least want to see when a game hangs in the balance.

Gardner? Maybe in the master blueprints in Tampa he’d have been a late-inning defensive replacement, with Aaron Hicks getting the nod in center field. But all Gardner has done, in what many thought was a victory-lap tour for the Yankees this season, is become he emotional fuse of the whole show, the original savage. He hit 28 homers this year — seven more than his previous career high — and he hit another Friday, and of all that happened this first night of the playoffs, that might have pleased the 49,233 inside the Stadium most.

They had plenty to choose from. Aaron Judge didn’t homer, but missed one by inches, and made two terrific plays in right field. Encarnacion clobbered two doubles his first two trips up, and looks primed to be a handful all October. Even Stanton avoided souring the good mood, drawing three walks.

The pitching? James Paxton was OK in his playoff debut. The army of relievers behind him was fine, even if it was puzzling why Aroldis Chapman was out there in the ninth with a six-run lead. Still, put it this way: If this is what the Yankees’ lineup is going to provide them on a regular basis across the next few weeks, there will be no complaints from them.

Or anyone else. After a long, hot summer, on a night filled with the splendid chill of October, the varsity Yankees were all in one place at long last. And it sure was something to behold.