SEATTLE — The Oakland Athletics aren't used to seeing anything go wrong when Grant Balfour's on the mound.
The A's closer hasn't blown a save in his last 36 chances, but he got his first loss in almost a year when he gave up a three-run homer to pinch-hitter Kendrys Morales in the 10th inning of a 6-3 defeat to the Seattle Mariners on Sunday.
Balfour (0-1) came on to start the 10th with the game tied, a situation he's not used to.
"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."
After getting a leadoff groundout, Balfour struck out Mike Zunino, only to have him reach first on a wild pitch. Balfour then worked Michael Saunders to a full count before Saunders singled and Zunino advanced to third. Morales then hit the first pitch he saw deep to right-center to end the game.
"The first pitch to Morales and the next thing you know it's three runs," Balfour said. "It's like you struck the guy out and you've got 3-2 — then base hit and it's one pitch, three runs. It happened pretty quick."
Oakland manager Bob Melvin said he was ready to use Balfour for two innings and wasn't going to wait for a different situation to bring out his closer once it went into the 10th.
"We had a couple guys who weren't available and he's our best pitcher," Melvin said. "We were going to go with our best guy going into the day off."
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.
Raul 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, to give Seattle a 3-0 lead. It was his second multihomer game this season and 18th of his career.
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.
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 Josh 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.