Mariners 4, Royals 1: Jason Vargas allowed one hit over eight brilliant innings to win his fourth straight start as host Seattle cruised to its eighth victory in 13 outings.
Mike Carp ripped a two-run single, Carlos Peguero had an RBI double and Brendan Ryan added a run-scoring single as the Mariners defeated the Royals for the fourth time in five games.
Billy Butler had both of Kansas City's hits and collected his 200th career double off Vargas to plate Lorenzo Cain in the fourth inning. Kansas City could not get its offense untracked en route to suffering its 18th loss in 24 games overall - and 11th in 14 outings on the road.
Vargas (11-7) shut down the Royals to improve his career mark to 4-1 against the club. Vargas also defeated Kansas City on July 16 when he yielded three runs on seven hits in six innings.
Tom Wilhelmsen struck out two in the ninth for his 12th save.
Carp opened the scoring in the first inning after his two-out single plated Dustin Ackley and John Jaso.
Luis Mendoza (4-7) saw his streak of four straight quality starts come to an end. The 28-year-old Mexican permitted four runs on nine hits in five innings.
GAME NOTEBOOK: Seattle has scored in the first inning in six of its last seven games. ... Butler has enjoyed success against Vargas, going 6-for-13 with two homers, two doubles and five RBIs in his career. ... Mendoza has yielded 14 runs on 23 hits in 14 innings lifetime versus Seattle.