"It's definitely been pretty crazy," Kelley said of the A's repeated late-game heroics. "I haven't seen anything like it. But it still doesn't mean we can't go out there and hold it down and keep us there and get the big outs we need to give our hitters another chance. You never like to lose, but to keep doing it in this fashion is no fun."
Oakland swept the series and improved to 91-68, including a 12-7 advantage over the Mariners this season.
The Mariners have lost 10 of their past 13 games, falling to 73-86 as they return home for a three-game series with the Angels to close out the season.
The A's stormed from a 4-1 deficit on Saturday to win in 10 innings, thanks to a two-run homer in the ninth and a three-run shot in the 10th. This time they did their damage an inning earlier and made it stand, thanks in part to a Mariners offense that left the game in doubt by failing to come up with any clutch hits.
"It's really been the story of our season offensively," said manager Eric Wedge. "Without a doubt, these kids have gotten better individually. But collectively we have to do better and finish off those things when we do create opportunities. To have 11 hits with only a couple runs, you have to do better than that. At times you just have to put the ball in play, shorten up and make contact."
Ramirez gave up just three hits, with four walks and six strikeouts, and turned a 2-2 tie over to his bullpen. The 22-year-old finished his first year in the Majors with a 1-3 record and a 3.36 ERA in 16 games, including eight starts.
But Seattle failed to capitalize on a leadoff double in the first inning, runners on first and third with one out in the fifth and runners on first and third with no outs in the seventh. They even came up empty after getting three hits in the second when Justin Smoak was thrown out at the plate by right fielder Reddick.
"It's frustrating for everybody," said Smoak. "You're up there trying your butt off to help the team win and you can't get the job done -- it's frustrating.
"When we've got guys on first and third with nobody out and nothing to show for it, it keeps them in the ballgame," he said. "And those guys over there have come back a lot this year and got big hits when they've needed [to]. When you get your opportunities, you've got to take advantage, and that's something we didn't do today."
Oakland totaled just three hits through the first seven innings, but capitalized immediately in the first with Cespedes hitting an RBI triple and then scoring on a sacrifice fly for a 2-0 lead.
Seattle finally pushed two runs across on four hits in the third on a double by Franklin Gutierrez, an infield single by Casper Wells, and RBI base hits by Kyle Seager and Smoak to tie the game at 2.
Seager increased his team lead to 84 RBIs, which puts him third among AL third basemen behind Miguel Cabrera and Adrian Beltre. Smoak went 2-for-4, and has hit .400 over the past 15 games to raise his average from .189 to .214.
The Mariners wound up with nine hits in 4 2/3 innings against A's starter Tommy Milone, but could only get the two runs.
That left the door open for the Oakland's late rally, and Cespedes and Reddick both fought back from 1-2 counts to hit their home runs off a Mariners bullpen that seems to be tiring down the stretch.
"They're hot and making things happen," said Luetge. "They're doing what a good team is supposed to do, and that's why they're in the position they are.
"I thought I had [Reddick] with a slider at 3-2, but he fouled that off. Then I left a fastball over the middle and he got it. He's got 32 home runs. You leave that right there, he's going to hit."
The A's have hit a Major League-leading 110 home runs since the All-Star break, including 20 in their last nine games.
"It's paramount for us," said Oakland manager Bob Melvin. "That's the way we've been winning here since June on. We haven't run much because we do have the power. It's been the deciding factor for us here down the stretch."