KANSAS CITY -- For their National League-leading 21st come-from-behind win of the season, the Reds had to reach down really deep on Monday night vs. the Royals. Like, really, really deep.

A short-handed Cincinnati bullpen meant reliever Ricky Karcher was needed to make his Major League debut in a pressure-packed save situation in the bottom of the 10th inning to protect a one-run lead. Veteran catcher Curt Casali had simple advice.

“The first thing I told him when he got on the mound before he started," Casali said, "[was] ‘Congratulations, you did it. You’re here. Go have some fun. Things are dicey as they are right now. Got a guy on second base, tight game. But try to enjoy it as much as you possibly can, because you only get one [debut].'”

Karcher, who was called up on Friday from Triple-A Louisville where he had a 9.27 ERA with command issues (34 walks in 22 1/3 innings), battled through wildness against Kansas City. But he and the Reds held on to a 5-4 victory in 10 innings -- their third straight and fifth in the past seven games.

"This is kind of our M.O. and what we do -- you grind out wins like that, it's awesome," said center fielder TJ Friedl, who scored the winning run in the 10th. "No matter what the score is at any time, we're going to fight until the last out no matter what."

Of the 21 pitches Karcher threw, only nine were strikes. His high-octane fastball wasn't just missing the plate, it was often missing by a lot. But Karcher had his slider working and found a way to finish the job after walking leadoff batter Bobby Witt Jr.

"You can only dream to go in a save opportunity in your first big league game. Obviously there was some adrenaline there," Karcher said.

Since the save stat was introduced in 1969, no Reds pitcher had debuted and recorded a save. The last time a debuting Major Leaguer notched a non-three-plus-inning save was Kwang Hyun Kim for the Cardinals on July 24, 2020.

“That’s a very, very difficult thing to do to have the toughness to stay with it like that," Reds manager David Bell said. "What a great way to start your career. It doesn’t really get much more difficult than that."

Closer Alexis Díaz wasn't available because he was used the previous two days. Lucas Sims and Ian Gibaut were also not available. Buck Farmer, who recorded the final two outs of the eighth inning, tried for the final three outs after Kevin Newman's pinch-hit sacrifice fly in the top of the ninth gave the Reds a 4-3 lead after they trailed 3-0 through two innings.

Farmer gave up a game-tying homer to Salvador Perez with two outs in the bottom of the ninth to force extra innings. By that point, Karcher already had a feeling he would make his debut after not getting into any of the three games in St. Louis. He admitted to becoming emotional in the bullpen.

"I had a moment there where I was about to tear up. Similar to whenever I found out that I was actually coming up here," he said.

As Karcher warmed up during the top of the 10th, Friedl was on third base when Jonathan India hit a grounder to third baseman Maikel Garcia. Running on contact with the infield playing in, Friedl slid home with his foot just ahead of the tag. Initially ruled out at the plate, the call was overturned on review.

"I just kind of tip-toed my foot in," Friedl said. "When they were showing the review, I knew my toe got in there briefly. Pretty ecstatic."

For the bottom of the 10th, Bell put the game in Karcher's hands.

After Witt's walk on five pitches, Karcher almost hit Michael Massey in the face with a fastball that was fouled off as he tried to bunt, then Massey flied out to Friedl. A double steal put both runners in scoring position, but Edward Olivares popped out to third base. Garcia's flyout to left field secured the Reds' win.

A relieved Karcher gave Casali a huge bear hug.

“I was just like, ‘We’ve got to work on your fastball, buddy,’” Casali said.

"That was just incredible," Karcher said. "Obviously, I don’t want to be in that situation, walking people and whatnot. It felt like I could have done better. But at the same time, the team won and I got the save."

When it was over, Karcher did a TV interview on the field as the entire team watched from the dugout while chanting, "Ricky! Ricky! Ricky!"

"That was really cool. It was cool to have them there," Karcher said.