BALTIMORE (AP) -- Two teams that rely heavily on the home run engaged in a long-ball duel at Camden Yards that had the fans in the bleachers running for cover.
In the end, Chris Davis' major-league leading 40th homer and a grand slam by Nate McLouth trumped four home runs by Seattle, and the Orioles held on for an 11-8 victory Friday night.
''It was the kind of a game where you felt like you had to outscore them,'' McLouth said. ''The ball was flying, and they're a really good hitting team.''
Seattle and Baltimore started the game ranked 1-2 in percentage of runs scored via the home run. This game bared out that statistic.
Davis and Ryan Flaherty hit solo shots prior to McLouth's first career slam. Seattle got a two-run homer from Michael Saunders and solo drives from Kendrys Morales, Michael Morse and Humberto Quintero.
''It was kind of one of those nights, both teams swinging the bats well,'' Davis said. ''It just seemed like it was going to be a battle of the offenses all night. One of those games where you feel like you can't score enough runs, no matter how many you put up there, they come back.''
McLouth connected off Brandon Maurer to make it 11-6 in the sixth, and that was just enough offense to fend off the Mariners. McLouth's homer followed three straight singles off Maurer, who entered after starter Aaron Harang (5-10) struggled through five shaky innings.
''If you look back, a lot of those pitches were over the heart of the plate,'' Seattle acting manager Robby Thompson said. ''If you do that to this club here, you're going to run into some problems.''
Jim Johnson worked the ninth to earn his 38th save and secure the victory for Chris Tillman (14-3).
Davis drove a pitch from Harang over the right-field wall and onto Eutaw Street to give Baltimore a 5-3 lead in the third inning. The solo homer traveled an estimated 442 feet and gave Davis a major-league high 101 RBIs.
He is the fifth Oriole to hit 40 homers in a season, joining Brady Anderson (50), Frank Robinson (49), Jim Gentile (46) and Rafael Palmeiro (43).
''It's pretty good company to be in,'' Davis said. ''I'm proud of the way things are going this year. Still got a lot more work to do, but it's nice to be a big part of a winning team.''
Adam Jones had three RBIs for Baltimore, which has won 10 of its past 12 against Seattle.
Tillman gave up a season high-tying six runs, as well as eight hits and three walks. But the right-hander improved to 5-0 in five career starts against the team that traded him along with Jones to the Orioles in 2008.
''It's an offensive night,'' Tillman said. ''Our guys did their job, and I give credit to their guys, too. They hit some good pitches and they battled.''
Morales went 4 for 4 and has 13 hits in his past 17 at-bats. But the Mariners have dropped four in a row and six of eight.
''We did a nice job offensively tonight,'' Thompson said. ''We put up some runs, but unfortunately we were playing catch-up all night long.''
Harang allowed seven runs and seven hits.
On Thursday night, the Mariners allowed six runs in the bottom of the ninth in an 8-7 loss to Boston. Thompson addressed his young team before this game to make sure there would be no carry-over.
''It's over and done with,'' Thompson said. ''I want to make sure we forget about it ... and move forward.''
They didn't. After going down in order with two strikeouts in the top of the first inning, Seattle promptly fell into a 4-0 hole.
McLouth singled and Harang issued two straight walks before Jones doubled in two runs, and another scored when left fielder Raul Ibanez mishandled the hit. Matt Wieters capped the uprising with a sacrifice fly.
Seattle used three walks, a homer by Saunders and an RBI single by Morales to close to 4-3 in the third.
After Davis homered in the third and Flaherty hit one in the fourth, Quintero connected leading off the fifth.
Jones hit an RBI single in the bottom half for a 7-4 lead, but the Mariners got two runs in the sixth on a run-scoring double by Morse and a sacrifice fly by Saunders.
NOTES: The Orioles placed 2B Brian Roberts on paternity leave as he awaits the birth of his first son. Baltimore filled out the roster by activating RHP Steve Johnson (strained oblique) from the disabled list. ... Seattle 2B Nick Franklin went 0 for 5 and is hitless in his past 17 at-bats. ... Roberto Alomar was inducted into the Orioles Hall of Fame before the game. ... Wieters went 0 for 3 and is hitless in his past 25 at-bats, the longest drought of his career.