Gomes rocked a three-run homer off an otherwise impressive Seattle starter in Jason Vargas, and Oakland lefty Tommy Milone delivered six strong innings to continue the club's recent theme of pairing a clutch long ball with a solid performance from a starting pitcher.
"We showed resiliency in these games," A's skipper Bob Melvin said. "We've just got to move on to the next city. It's certainly a better feeling than it was when we left [Oakland]."
With their third straight victory, the A's maintained a half-game lead in the American League Wild Card race. The win was also Oakland's ninth consecutive on the road, its longest streak away from home since 2002.
Oakland only managed five hits -- four off Vargas -- but one of them proved to be the difference. With runners at first and second in the fifth inning, Gomes sent a 1-1 fastball off the second-deck facade in left field to give Oakland a 3-0 advantage. The 31-year-old is hitting .301 with eight homers and 20 RBIs in 28 games since the All-Star break.
Clutch home runs have been the winning blueprint for the A's on offense in the past few days, and it wasn't always like that this season. Melvin likes the fact that his team is finding new ways for production at the plate.
"We feel like we don't have to string hits together to score runs," he said. "We can now do it via the long ball and do it in a hurry. Even if we're bogged down a few innings, all of a sudden after one pitch we can get a run on the board."
Milone got off to a blazing start, striking out five of the first six batters he faced. But the rookie gave up eight hits in the next four innings, including a two-out RBI triple to Michael Saunders in the fifth and a solo shot to Kyle Seager in the sixth that cut Oakland's lead to 3-2.
It could have been worse, but Milone escaped several jams. He threw three two-out strikeouts with runners in scoring position in the fourth, fifth and sixth frames. That was enough for the righty's 12th victory of the season -- tying the A's rookie record -- as Milone went six innings, giving up eight hits, two runs and matched a season-high with 10 strikeouts.
Milone also continued to avoid walks and tied a team record for walking one hitter or fewer in each of his last 14 starts.
"I've always been a strike thrower," he said. "I feel like there's nothing good about giving a free pass."
Pat Neshek and Jerry Blevins worked a perfect seventh, and Ryan Cook matched the effort in the eighth before Josh Donaldson's seventh home run of the season gave Grant Balfour an insurance run to work with in the ninth.
Balfour worked around a leadoff double to earn his 16th save of the season.
Oakland will head south to Los Angeles for a four-game set against the Angels beginning Monday.