SEATTLE -- The last time Kendrys Morales hit a game-ending home run his celebration quickly turned into a nightmare.
It was the first game-winning home run for Morales since May 29, 2010, when as a member of the Angels he broke his ankle jumping onto home plate in celebration. The injury led to multiple operations and sidelined him for nearly two years.
This time, there was no final leap -- with the mob of teammates surrounding home giving him plenty of space, Morales simply jogged to the plate before his teammates closed in to celebrate.
"That was a learning experience for me," Morales said through a translator. "I can't do that anymore, but I've got to celebrate this win."
Raul Ibanez started the game at designated hitter in place of Morales and hit a pair of home runs for his second multihomer game this season and 18th of his career.
Seattle manager Eric Wedge said before the game he wanted to give Morales a rest, saying, "We've pushed him hard and he's been struggling the last week."
Wedge told Morales not to start warming up for a possible late-inning appearance until at least the sixth inning.
"He was more than ready those last two or three innings," Wedge said. "I think he had his helmet on the last two innings ready to hit. he was chomping at the bit to get up there."
With one out in the 10th Mike Zunino struck out but reached first on a wild pitch. He advanced to third on Michael Saunders' single before Morales hit the first pitch he saw from reliever Grant Balfour (0-1) deep to right-center field. It was the Oakland closer's first loss since June 29, 2012.
"I wasn't expecting the call, I guess," Balfour said. "I guess I'm waiting for us to score to go in and save the game. So I didn't have the right mind frame going in, maybe."
Morales said he wasn't sure the ball was out until it landed, and Zunino also waited to be certain.
"I thought he did enough to do the job to hit a sac fly," Zunino said. "I was just sitting on third base -- I wanted to see it land before I took off."
Right fielder Josh Reddick appeared to be far more sure, putting his head down and starting to jog off the field while the ball was still in the air.
Ibanez gave the Mariners the lead with a two-run homer in the first inning and added a solo shot in the third, his team-leading 17th and his third home run in two games.
"I'm just trying to hit the ball on the barrel and things are working out," Ibanez said.
Oliver Perez (2-1) pitched two innings to earn the win. Perez has not allowed a run in his last 11 innings.
Brandon Moss' solo home run off reliever Danny Farquhar in the eighth inning tied the game at 3.
Oakland started the day in a tie with Texas for the American League West lead but has lost four of five. The bullpen has been an issue in the recent slide -- before Sunday, the A's bullpen had blown three games. Relievers picked up three losses and only one save over the previous six games.
Seattle starter Jeremy Bonderman, who had allowed two runs over his previous three starts, cruised until getting into a jam in the sixth as the Athletics loaded the bases with one out.
With a 2-2 count on Josh Donaldson, Bonderman threw a wild pitch that allowed Jed Lowrie to score. Bonderman walked Donaldson on the next pitch to load the bases again and was relieved by Farquhar.
Farquhar got Reddick to groundout to second base, but Nick Franklin had to make a sliding stop and could only get the out at first as Yoenis Cespedes scored to make it 3-2. Farquhar then got out of the inning when pinch-hitter John Jaso grounded out.
The Mariners were in position to add to their lead in the seventh with runners on the corners and one out, but Saunders grounded into a double play.
Oakland starter Jarrod Parker kept his four-game winning streak alive with a no-decision, giving up three runs on five hits with one walk and six strikeouts in six innings.
- After the game Oakland optioned RHP Dan Straily to Triple-A Sacramento.
- Seattle CF Franklin Gutierrez, playing for the second straight game after coming off the 60-day DL, left the game after the sixth inning with a tight hamstring. "We'll see how he feels in a couple of days," Wedge said.
- CF Coco Crisp was the only Oakland starter that had previously faced Bonderman. Crisp is now 10 for 45 with a home run against the right-hander.
- It was the Mariners' first game-ending home run since Sept. 14, 2011.