Updated

Baltimore, MD (SportsNetwork.com) - Chris Tillman outdueled Hisashi Iwakuma on Sunday, tossing seven scoreless innings to help the Baltimore Orioles take the rubber match of a three-game set with a 1-0 decision over the Seattle Mariners.

Tillman (8-5) has dominated Seattle over his career, improving to 6-0 in six career meetings. The young right-hander struck out six and allowed just four baserunners during his 101-pitch outing.

"Starting pitching is starting to show up for us ... we're feeding off each other," Tillman said.

Iwakuma (9-6) was nearly flawless after Nick Markakis led off the bottom of the first inning with a solo homer. He fanned seven in 7 2/3 innings of work.

Iwakuma has gone at least seven innings in six straight starts.

"We've played them seven games and I thought we played them pretty good," Mariners manager Lloyd McClendon said.

Markakis had three of Baltimore's five hits, including his 22nd double of the season. He finished a triple shy of the cycle.

The O's improved to 30-25 at home and padded their slim lead on top of the American League East standings with the win. They will travel to Washington for one game on Monday before a crucial three-game series in Toronto against the Blue Jays, who sit in second in the AL East.

Markakis fell behind 1-2 on Iwakuma before working the count full. He then deposited the sixth pitch of the at-bat onto the concourse in right field. Iwakuma responded by striking out the side.

Tillman retired 14 straight batters at one point before Kendrys Morales singled to center to start the seventh inning. Kyle Seager followed by grounding into a routine 4-6-3 double play, and Chris Denorfia grounded out harmlessly to end the stanza.

Zach Britton came on in the ninth and secured the game, pitching around a two- out walk to Robinson Cano to earn his 23rd save.

Game Notes

Orioles slugger Chris Davis returned to the lineup after missing Saturday's game with a stomach virus ... Seattle did not have an extra base hit ... Both of Iwakuma's losses since July 1 have come against Baltimore ... Iwakuma walked two batters for just the third time this season. He has 101 strikeouts and 11 walks in 125 1/3 innings ... Seattle has not won back-to-back games since July 11-12 against Oakland.