SEATTLE -- A shift that didn't work and a throw that was too hot to handle after it hit the ground in front of home plate were largely responsible for the Mariners absorbing a one-run loss to the Athletics on Saturday night.

Those two plays produced single runs in the eighth and ninth innings, and for just the second time this season, the Mariners lost a game in which they led after seven innings, dropping a 3-2 decision before 29,484 on Turn Back the Clock Night at Safeco Field.

Seattle had been 12-1 when leading after seven innings. But the bullpen had been restructured before the second game of the series.

In something of a surprise, the Mariners put closer Brandon Morrow on the 15-day disabled list with biceps tendinitis, retroactive to April 24.

At least it was a surprise to Morrow, who thought the ailment that has kept him out of action for more than a week was healed enough for him to pitch. He was not thrilled with the decision.

With Morrow out, the tandem that has worked well this season -- David Aardsma pitching the eighth inning and Morrow the ninth, was not available.

A different approach was necessary.

"Without Morrow there, we're asking guys to step up and every opportunity we give them is a learning experience," manager Don Wakamatsu said. "We have some young guys who will benefit from it later in the season."

One of them is right-hander Mark Lowe.

He picked up for starter Jarrod Washburn after seven innings and promptly surrendered a one-out double and two-out single to erase the one-run lead the Mariners grabbed in the bottom of the seventh on a bases-loaded sacrifice fly to left field by Endy Chavez.

As most teams do when Jason Giambi comes to bat, the Mariners put three-fourths of their infield on the first-base side of second. The strategy works more times than not.

This time, it didn't.

Giambi fought off a 97-mph fastball and rolled it up the middle -- too far from either third baseman Adrian Beltre or shortstop Yuniesky Betancourt to stop.

"It's tough when you get beat on a shift like that," Washburn said. "The shift works almost every time, especially against a guy like Giambi. But that's how smart of a guy he is. All he has to do there is get a little single and his team gets a run. That's a good piece of hitting by him."

With their lead gone, the Mariners entered the ninth inning hoping to at least still be tied when they came to bat in the bottom of the ninth.

Aardsma, who has three saves this season and is holding opposing hitters to a .074 batting average, issued a one-out walk to Bobby Crosby, and it came back to bite him in a big way. Crosby stole second on a close play and then scored the go-ahead run on Gregorio Petit's two-out single to right field.

Ichiro Suzuki came in quickly, fielded the ball on the second hop and came up throwing. His on-target peg landed in the worst place for catcher Rob Johnson -- causing a tricky bounce.

Johnson was unable to catch the ball and was bowled over at the plate, adding a little pain to the play.

"[Johnson] tried to stay in there and hold on to the ball," Wakamatsu said, "but it's a tough play, especially with a guy bearing down on you. He did just about everything he could.

"It was just one of those inches-away plays. If he catches it cleanly, [Crosby] doesn't score."

The Mariners' offense was limited to Chavez's sac fly and another home run from first baseman Russell Branyan. He hit his sixth of the season, and second in two nights, with a leadoff blast to center field in the second inning.

But the most positive aspect of the game, which saw the Mariners lose to the Athletics for the first time this season and snap a seven-game winning streak against their American League West rivals, was Washburn's performance.

"Wash was outstanding again," Wakamatsu said. "I thought he really pitched well. It was more indicative of his first three starts, and not his last one."

The veteran lefty agreed.

"That last start [against the Angels] was a blip on the screen," he said. "I wanted to get back on track and I did that tonight. Everything was working for me."

The only mistake he made was leaving a first-pitch slider to Giambi in the sixth inning up too high. Giambi drilled it into the right-field corner to score Petit from first base and erase the one-run lead Branyan had provided.