KANSAS CITY, Missouri (AP) ― Buck Showalter knew he was in trouble when the seventh inning rolled around and his Orioles were trailing the Kansas City Royals in Game 4 of the AL Championship Series.

Three innings later, Baltimore’s season was over.

In each game of the series, the three-headed monster of Kelvin Herrera, Wade Davis and All-Star closer Greg Holland had slammed the door on the Orioles. They did it again in the clincher, a 2-1 victory that propelled Kansas City into the World Series after a 29-year absence.

Game 1 is Tuesday night against the San Francisco Giants.

“That’s one of the biggest reasons they’re playing here,” Showalter said of the “Big Three.”

The Royals had one of the stingiest bullpens in baseball this season, but the back end was especially dominant. Herrera, who usually handles the seventh inning, had a 1.41 ERA in 70 games. Davis, the eighth-inning guy, had a 1.00 ERA in 71 appearances. And Holland had a 1.44 ERA while saving 46 games, one shy of his franchise record set just last season.

They were at their best in sending the Royals to the World Series, too.

Herrera pitched 5 2/3 scoreless innings against Baltimore, allowing just two hits. Davis went five scoreless innings, also giving up two hits. Holland was the only one to give up a run, but he still managed to save all four games, joining Hall of Famer Dennis Eckersley as the only pitchers to accomplish the feat since the ALCS went to a best-of-seven format.

“At the end of the game,” Royals starter Jason Vargas said, “we like our chances.”

All three relievers have four-seam fastballs that approach 100 mph, and all three have a devastating secondary pitch. Herrera has a lightning-quick two-seamer, Davis’ new cutter has been dynamic, and the vicious slider that Holland can unleash leaves hitters waving at air.

But that’s where the similarities end. The three of them took very different paths to reach this point, key cogs in a perfectly tuned strikeout machine.

Herrera exploded onto the scene two years ago, a fireballer who never seemed to quite know where his fire balls were headed. What little command he had finally failed him last season, and he was banished to the minor leagues, where he was able to rein everything in.