Orioles 1, Mariners 0: Chris Tillman pitched seven scoreless innings to continue his dominance against Seattle as host Baltimore won the series finale.

Nick Markakis had three of the five hits for the Orioles, including his ninth home run of the season. Tillman (8-5) allowed four hits without a walk and struck out six in improving to 6-0 in six career starts against the Mariners.

Recently acquired Andrew Miller worked a perfect eighth inning and Zach Britton pitched around a two-out walk in the ninth for his 23rd save to help Baltimore prevail in the series rubber game and move 3 1/2 games ahead of second-place Toronto in the AL East. Seattle starter Hisashi Iwakuma (9-6) gave up just one run and five hits with seven strikeouts in 7 2/3 innings to end a 14-start road unbeaten streak dating to July 4, 2013.

Markakis accounted for all the scoring with a leadoff home run in the first on a 3-2 offering from Iwakuma. He later singled in the third for his 1,500th career hit and doubled in the sixth, though he was stranded at second.

Seattle put two runners on base in the second inning, but Tillman struck out the final two hitters to begin a stretch of 14 straight batters retired. Kendrys Morales opened the Mariners' half of the seventh with a base hit but was quickly erased on a double play, and Miller and Britton closed it out from there.

GAME NOTEBOOK: Orioles OF/DH Nelson Cruz, who is mired in a 1-for-28 slump, was given the day off. ... 3B Kyle Seager had a single and a stolen base to highlight a quiet day offensively for Seattle. ... The Mariners kick off a nine-game homestand on Tuesday, beginning with a pair of games against the Atlanta Braves. The Orioles head to Washington for a makeup game against the Nationals on Monday before visiting Toronto for three games.