KANSAS CITY, Mo. -- Brandon Moss has homered in back-to-back games, which is what the Kansas City Royals have been hoping to see from their designated hitter.

Moss hit the go-ahead home run in the sixth inning and Nathan Karns struck out a career-high 12 in a no-decision as the Royals held on to beat the Baltimore Orioles 4-3 on Saturday night.

"I'm definitely feeling better in the box," Moss said. "Every day is a different day. I'm seeing the ball better, definitely. So hopefully it will start to turn around a little bit more."

It is the 16th time in Moss' career he has homered in back-to-back games.

"If he gets hot, he can carry a team with his power," Royals manager Ned Yost said.

Royals relievers Mike Minor and Kelvin Herrera retired the final nine Orioles.

Karns has struck out 22 in his past two starts, becoming the sixth Royals starter to strikeout 10 or more in back-to-back games.

The Royals scored two runs in the bottom of the fifth to grab a 3-2 lead. Alcides Escobar and Mike Moustakas led off the inning with singles and each moved up 90 feet on a Chris Tillman wild pitch.

Lorenzo Cain's sacrifice fly scored Escobar. Tillman walked Eric Hosmer and was replaced by Alec Asher, who hit Salvador Perez with a pitch to load the bases. Jorge Bonifacio's flyout to left fielder Trey Mancini got Moustakas home.

Royals manager Ned Yost elected to pull Karns after 91 pitches and five innings. Karns said he "definitely" had something left in the tank to go out for the sixth.

"It's a good ball club we've got coming in," Karns said. "They're one of the top in the league. I had kind of a long inning. I labored through the fifth. We have a great bullpen and they did an amazing job the last four innings, got us a 'W' and that's all I care about at the end of the day."

Karns had a very effective curveball to keep the Orioles off balance.

"I'm finding success when I'm able to work ahead I can really expand the zone," Karns said. "Today it's a very powerful lineup and I knew I had to keep it down. I had success with it. I guess they weren't picking it up and I kept going with it."

Yost brought in Seth Maness, who had not pitched in the majors since Aug. 13 and had elbow surgery.

It took Maness three pitches to blow the lead. Chris Davis hit a 2-1 pitch out to left, just clearing the fence into the Royals' bullpen.

"I'd like not to blemish Karns' awesome start, but it's good to get back out there," Maness said.

The Royals regained the lead in the bottom of the inning on Moss' leadoff home run to right.

Karns struck out five in a row during one stretch but was not fooling Orioles No. 9 hitter Francisco Pena.

Pena, a former Royal and the son of former Kansas City manager Tony Pena, homered twice off Karns in the first five innings to give the Orioles a 2-1 advantage.

"Having all my ex-teammates there, and I know they're not happy when it happened, but they felt a little bit proud watching me grow as a player," Pena said. "I was with them in 2014. I was with them in 2015 and it was a very special group when we went to the World Series twice in a row. I think it was special and really nice. It was special because it was in Mother's Day

weekend."

Pena smashed a 2-2 Karns offering with one out in the third. Pena's shot landed at the back of the Kansas City bullpen.

With two outs in the fifth, Pena turned on the first pitch and belted it out to left. It was Pena's first career multi-homer game.

"I hung the curveball the first at-bat," Karns said. "He did a great job of hitting it out. He ambushed the heater on the next at-bat and made solid contact. You've just got to tip your cap. Two bad pitches by me and he capitalized on them."

Orioles starter Chris Tillman was removed after 4 1/3 innings 105 pitches, allowing three runs on eight hits.

Hosmer led off the Kansas City second with an opposite-field double and came home on Perez's single.

"I don't think it's a step back," Tillman said. "I think every step is a step forward as long as you physically feel good. Mechanically, I got out of my way, to start. Just trying to do too much later in the game."

NOTES: Royals LF Alex Gordon was held out of the lineup with a strained right groin, which caused him to exit in the seventh inning Friday. It is not considered serious. ... Orioles 1B Chris Davis returned to the lineup after being given Friday off. ... Orioles 2B Jonathan Schoop went 0-for-4, ending his consecutive streak of reaching base safely at a career-high 26. ... Orioles RHP Kevin Gausman and Royals RHP Chris Young are the Sunday probables for the series finale.