SEATTLE -- Maybe Mike Moustakas was just warming up for the Home Run Derby.

Moustakas hit a solo homer off the facade of the second deck in right field Monday night at Safeco Field, just below the Hit It Here Cafe, as the Kansas City Royals defeated the Seattle Mariners 3-1.

It was the 23rd home run of the season for Moustakas, not only breaking his career high but also the team record for the most before the All-Star break. Jermaine Dye hit 22 before the break in 2000.

"I'm just trying to go out there and get hits," Moustakas said. "Getting some good pitches, putting some good swings on them, and the ball is going out."

It was announced during the game that Moustakas would participate in the Home Run Derby on July 10 in Miami, the day before the All-Star Game.

"I'm really excited. It's going to be an awesome experience," he said. "I've never been to Miami, so I'm excited to go there and have some fun in the Home Run Derby."

Moustakas is also one of five finalists for the final spot on the American League team for the All-Star Game, to be determined by a vote from fans.

"Hopefully that still happens," said Moustakas, who won the final vote in 2015 to make his first All-Star Game.

Alex Gordon also hit a solo home run, his fifth of the season, to back a strong outing from Kansas City starter Ian Kennedy (3-6).

Kennedy allowed one run on four hits in 6 2/3 innings, with two walks and seven strikeouts, to win his third consecutive decision.

Relievers Peter Moylan, Neftali Feliz and Joaquim Soria combined for 2 1/3 perfect innings to close out the victory. Soria got the last three outs for his first save of the season.

"Kennedy had the little blip in the second inning where he walked a couple of guys and gave up the one run, but after that, he was great in every inning," Royals manager Ned Yost said. "He had a really good curveball, commanded his stuff extremely well and just pitched a great game."

That was important for the Royals, who played a doubleheader Saturday against Minnesota and used five relievers to beat the Twins on Sunday.

"It was a long weekend," Kennedy said. "No matter what, you try to go as deep as you can."

The Royals (42-40), who lost 20 of their first 30 games, moved two games above .500 for the first time this season and prevented the Mariners (41-43) from returning to the .500 mark.

Kansas City struck early against Seattle right-hander Andrew Moore, who was making his second major league start.

Whit Merrifield led off the game with a double into the right field corner. Merrifield advanced to third on a Ramon Torres flyout to center field and scored on Lorenzo Cain's sacrifice fly to right.

Kansas City made it 2-0 in the second as Moustakas led off with his homer.

The Mariners scored in the bottom of the second, but Kennedy did well to limit the damage.

With one out, Kyle Seager walked, Danny Valencia grounded a single up the middle, and Jarrod Dyson walked to load the bases. Seager scored on a wild pitch, with Valencia and Dyson also advancing. Kennedy struck out Mike Zunino and Boog Powell to end the threat.

"Getting out of the second with two strikeouts was big to stop any rally," Kennedy said.

Moore retired 11 consecutive batters after Moustakas' home run.

Gordon snapped that streak with two outs in the fifth, hitting a broken-bat home run into the first row of seats in right-center field, just over the outstretched glove of Mariners right fielder Mitch Haniger. The blast gave the Royals a 3-1 lead.

The Mariners threatened in the seventh as Valencia led off with a single and took second on a wild pitch. With two outs, Moylan relieved Kennedy with pinch hitter Nelson Cruz coming up. Moylan struck out Cruz to end the inning.

Moore went eight innings, allowing three runs on five hits. He struck out four without issuing a walk.

"For his second major league start, Moore was very impressive," Mariners manager Scott Servais said. "He made some good in-game adjustments.

"They hit some balls out of the park, and we didn't get much going offensively."

NOTES: Royals 1B Eric Hosmer went 2-for-4 to extend his hitting streak to 10 games. ... The Mariners optioned RHP Dan Altavilla, who was 1-1 with a 5.46 ERA in 29 relief appearances, to Triple-A Tacoma to make room on the roster for RHP Andrew Moore. ... Seattle made a trade just before the game, sending Double-A RHP Tyler Herb to the San Francisco Giants for cash considerations. ... Royals LHP Danny Duffy (4-4, 3.54 ERA) is scheduled to be activated from the 10-day disabled list Tuesday to start against Mariners RHP Felix Hernandez (3-2, 4.66). Duffy has been out since May 28 with a strained right oblique.