Luis Castillo and the Seattle bullpen held the Kansas City offense in check as the Mariners came away with a 2-0 win Thursday afternoon at Kauffman Stadium.

Castillo scattered three hits across six scoreless frames to pick up his tenth win of the season. Jorge Polanco put the Mariners ahead in the second inning with an RBI double, scoring Josh Naylor.

Seattle struck again in the eighth after an RBI double courtesy of J.P. Crawford.

Kansas City wasted a strong outing from Steven Kolek, who went seven-and-a-third innings, allowing two runs on two hits and a walk with eight strikeouts.

The Royals had the tying run on base in the ninth, but Andrés Muñoz was able to strike out the side to earn his 36th save and secure the series win for Seattle.

The Royals are now back below .500 and fall to seven games back of Boston for the third wild card spot, with only nine games remaining on their schedule. The Royals will next host the Toronto Blue Jays for the start of a three game series. Kansas City will send Michael Lorenzen to the mound to face Max Scherzer. First pitch will begin Friday at 6:40 p.m.