Moustakas went 3-for-5 with three RBIs for Kansas City, which racked up 13 hits. Drew Butera and Alcides Escobar had two RBIs apiece for the Royals.

The right-handed Junis (2-0) gave up his lone hit with one out in the seventh inning. He struck out three, walked two and hit three batters.

It was the second straight stellar outing for Junis, who has given up no runs and four hits over 14 innings this season.

Junis worked around some control issues over the first six innings, and he started the seventh well by inducing Kyle Seager to hit a comebacker for the first out.

Daniel Vogelbach followed with a hard liner up the middle that sailed past Junis. Escobar, the shortstop playing just to the right field side of second base, dove to his right and was able to knock the ball down but had no play at first.

Junis retired the next two batters before exiting. The Mariners finished with two hits.

Seattle left-hander Marco Gonzales (1-1) lasted just 2 1/3 innings and allowed four runs and eight hits. He struck out four and walked one.

Kansas City led 2-0 just three batters into the bottom of the first when Moustakas laced a two-run double to center. Jorge Soler singled to center later in the inning, and the ball was misplayed by Mariners center fielder Dee Gordon, allowing Moustakas to score.

Soler singled to lead off the third inning, moved to third base on Paulo Orlando's double and later scored on Escobar's infield out to increase Kansas City's lead to 4-0.

The Royals broke the game open with a five-run fourth inning off Seattle right-hander Casey Lawrence.

Orlando's fielder's choice plated the inning's first run, and the second came across on Cam Gallagher's RBI double to left field. Escobar's run-scoring infield single made it 7-0, and Butera capped the splurge with a two-run double to left-center field.

Moustakas homered to right in the bottom of eighth off Seattle's Taylor Motter, an infielder sent out to pitch due to the one-sided margin. Motter struck out one, walked one and hit a batter in addition to serving up Moustakas' first homer of the campaign.

--Field Level Media