NEW YORK — The moment that defined a rivalry came 47 years ago Sunday. It was a cool fall night in the Bronx, Game 2 of the 1977 ALCS, and Hal McRae stood on first base. The Kansas City Royals were trailing the New York Yankees 2-1 in the sixth inning, but McRae had an idea, so he hollered over to teammate Freddie Patek, who was on second.

“I motioned to Freddie,” McRae, now 79, said from his home in Florida on Friday. “If we got a ground ball, I was gonna take out the middle infielder.”

Sure enough, the Royals’ George Brett slapped a grounder to Yankees third baseman Graig Nettles, who fired to second baseman Willie Randolph, and that’s when it happened, that’s when — BOOM! McRae didn’t so much take out Randolph as obliterate him — a rolling body block that began with McRae catapulting himself head first into Randolph’s thighs and both players landing in a heap at least 10 feet from second base. The collision caused Randolph to drop the ball, which allowed Patek to scamper home, which caused Yankees manager Billy Martin to fly out of the dugout in a rage and Randolph to scream something at McRae.

“When I was walking off the field,” McRae said, “he threw the ball at me.”

To watch the clip now is to take a portal to a different dimension of baseball, one before phrases like big market and small market, before players fraternized like country club pals, when a rivalry could be measured in hatred, punches and public broadsides. More than four decades ago, the Yankees and Royals faced off in the ALCS four times in five years. On one side was the Bronx Zoo-era Yankees — Billy Martin, Thurman Munson, and later Reggie Jackson — the game’s glamour franchise. On the other was an expansion team from flyover country with a Hall of Famer at third base and speed to burn. The result wasn’t a baseball series; it was closer to a blood sport.

“It’s a (expletive) war,” Brett, the Royals Hall of Fame third baseman, said Friday, standing near the third-base dugout at Yankee Stadium. “That’s what it was back then.”

The old rivalry is over, but the postseason series resumes on Saturday night when the Yankees host the Royals in Game 1 of the ALDS, the first postseason series between the clubs since 1980. Gone are Brett and Martin; enter Aaron Judge and Bobby Witt. Jr.

For many of the old Royals, the history brings to mind a mix of emotional scar tissue — from three ALCS losses in 1976 to 1978 — and salvation after a breakthrough in 1980. But after more than four decades, it has also forged a common bond: They were the team that gave the Yankees their best shot. They waged a baseball battle in the Bronx and lived to tell the tale.

“We hated each other,” former catcher Buck Martinez said. “That’s all there is to it.”

“They were the empire,” former catcher Jamie Quirk said, “and we were the new ones on the block.”

“It was just classic stuff that you’ll never forget,” former outfielder Clint Hurdle said. “It was almost like we were able to play a game in the wild, wild west.”

Hal McRae, shown here after stealing 2nd in 1978, was a catalyst in the Yankees-Royals rivalry. (Focus on Sport / Getty Images)

In the moments before Game 1 of the 1976 ALCS, Brett was next to Martinez inside the home clubhouse in Kansas City. They had been roommates in the minor leagues and teammates with the Royals, but this was their first playoff game.

“We were both sitting there really nervous as hell,” Martinez said. “And I asked him: ‘Are you nervous?’ He goes: ‘Yeah.’ I said: ‘So am I.’ ”

A few minutes later, Brett made two errors in the first innings. Martinez, behind the plate, yelled over to third: “You’re OK now.”

The Royals, in their eighth season as a franchise, were finally in the postseason after toppling the Oakland A’s in the AL West. The Yankees, meanwhile, had broken a dry spell and reached the postseason for the first time since 1964. Compared to the series that would follow, the 1976 ALCS was a relatively tame affair, most famous for its dramatic Game 5 in the Bronx.

With the score tied 6-6 with two outs in the top of the ninth, the Royals put runners at first and second before Jim Wohlford hit a slow bouncer to third and Royals outfielder Al Cowens was forced out at second on a controversial call. For reasons that still confuse Martinez, the third out of the inning caused Yankees fans to litter the field with toilet paper streamers and trash. As Royals pitcher Mark Littell headed to the mound to warm up in the ninth, the game was delayed as the grounds crew tried to clear the field.

“We were on the field, it seemed like an eternity,” Martinez said.

Brett still isn’t sure if the delay affected Littell, but he does know what happened moments later: Littell threw one fastball to New York’s Chris Chambliss, who took a violent cut and blasted a game-winning homer to right-center field. When the ball cleared the fence, hundreds of New York fans began pouring onto the field. Brett made a beeline for the third-base dugout. Martinez sprinted in from home plate. But McRae, out in right field, had no clear path to the dugout, so he sprinted across the outfield, where he found refuge in an open gate in left field.

“The door was open, so I ran to that area,” McRae says. “It was a scary feeling. Because the fans were pouring on the field, and I didn’t know what was gonna happen.”

Yes, this was the tame series.

The next year, in the fall of 1977, the Royals and Yankees would meet again in another five-game classic, one filled with collisions, brawls and pages and pages of verbal fisticuffs. At one point during the series, Martin, the Yankees’ fiery manager, made it a point to tell writers that he was excited to face pitcher Larry Gura, a former Yankee, in Game 4.

“My only worry I have is that he doesn’t get hurt on the way to the ballpark,” Martin told reporters, over and over. “I mean, in an accident or anything. Maybe I ought to send a bodyguard to his home.”

And that was nothing compared to what transpired before Game 4, when the Yankees’ Cliff Johnson, still furious over Randolph getting destroyed, spent most of batting practice yelling at the Royals’ McRae.

A 32-year-old in his ninth season, McRae was unfazed. He had come up in Cincinnati, where he had learned to emulate the playing style of teammate Pete Rose. He sprinted on every ground ball. He held teammates accountable. Whenever teammate Dennis Leonard made a start, McRae would hold up a few fingers as Leonard walked to the bullpen to warm up. That was how many runs the Royals would score that day.

The cross-body block, however, was his own invention.

“Because I knew I could make contact and he wouldn’t be able to throw to first base,” McRae said.

Suffice it to say, McRae was not the kind of man who had time for Johnson, a backup player.

“I told Cliff,” McRae said. “I’m not gonna get into a fight with an ‘extra man.’”

Nevertheless, the Yankees won Game 4 in Kansas City, which set up a winner-take-all Game 5 made famous for its first-inning brawl between Brett and Graig Nettles. Brett hit an RBI triple and came in hard to third base. Nettles gave him a little kick. More than a little perturbed, Brett threw an overhand haymaker, setting off a wild skirmish that included Yankees catcher Thurman Munson covering up Brett at the bottom of the pile — “He just kind of protected George on the ground,” Martinez said — and starting pitcher Ron Guidry jumping into the fray.

Graig Nettles and George Brett fighting at third base (Getty Photos)

“I remember George came back to the dugout and goes: ‘He kicked me,’ ” Quirk said.

Nobody got thrown out.

“The umpires dust everybody off,” Martinez said. “And then they said: You guys done now? OK, let’s go.’”

This time, the Royals took a 3-2 lead into the ninth. But the Yankees struck for three runs, winning a second straight AL pennant on their way to their first World Series championship since 1962.

“That was probably the one that was most heartbreaking for us,” starting pitcher Dennis Leonard said. “Because I honestly felt we had the best team in baseball. But they won. What are you gonna say?”

The Yankees would win again in 1978. It didn’t matter that Brett hit three homers off Catfish Hunter in Game 3; the Yankees won the game 6-5 and took the series in four. The Royals and Yankees would both miss the playoffs in 1979, but they met for a fourth time in 1980. This time, the Royals had a closer: Dan Quisenberry. Brett homered off Goose Gossage in Game 3. They took the series in three games.

The 1980 Royals would lose the World Series to the Phillies in six games, and it would take another five years to finally win their first World Series. But for many of the players, beating the Yankees at last was almost as good as winning it all.

“I was playing right field when Dan Quisenberry struck out Willie Randolph for the last out,” former Royal John Wathan said. “That’s the first and only ever time I’ve cried in baseball.”

A funny thing happened one summer day in the 1990s. Wathan attended a charity golf tournament that featured a collection of old Royals and Yankees from the late 1970s, two groups that had spent four Octobers hating each other.

“You actually realize they’re pretty good guys,” Wathan said, laughing.

Friendships have bloomed. War stories have been traded. Hurdle lives near Bucky Dent in Florida and still marvels at the competitiveness of Lou Piniella and Munson, who died 10 months after the 1978 series.

“Because all they wanted to do was beat your ass,” Hurdle said. “And looking at those two, what better guys to have on your team than guys that just want to beat the other team’s ass.”

Nearly a half-century later, Brett has made a similar peace. He doesn’t hate those players anymore. But he still hates the Yankees. He can’t help it.

McRae takes it one step further.

“I don’t think we hated the guys,” McRae says. “We hated the Yankees. Because they had all the advantages, we felt. They had the resources to sign players. We were jealous that they could do things that we couldn’t do. And I think that was the essence of it.”

On the eve of another playoff battle between Kansas City and New York, McRae told another old story, one that is not quite as famous as Randolph getting taken out or Brett and Nettles brawling. When the final out was recorded in 1977, after the trash-talking and brawls were done, a few Royals walked over to the Yankees clubhouse.

“We went over and we sat around and congratulated them,” he said. “It was over. The war was over.”

(Top photo of Yankee catcher Thurman Munson trying to block George Brett from scoring: Focus on Sport / Getty Images)