Brandon Moss' leadoff homer in the sixth proved to be the difference, as the Oakland Athletics held off the Seattle Mariners, 4-3, on Saturday in the middle test of a three-game series at Safeco Field.
Josh Donaldson and Daric Barton each added a solo shot, while Jed Lowrie collected three hits and knocked in the other run for the A's, who snapped a five-game slide.
Jarrod Parker (2-5) allowed just three runs on three hits and four walks while striking out five over 6 1/3 innings. Grant Balfour stranded runners on first and second in the ninth to nail down his sixth save of the season.
"We want to get him on a roll," A's manager Bob Melvin said of Parker. "We'd like to see him get on a roll and certainly with losing a few games in a row, it was a performance we needed out of him."
Kelly Shoppach scorched a two-run homer and Dustin Ackley added an RBI single for Seattle, which had won two straight coming into the game.
Brandon Maurer (2-5) yielded three runs on six hits and two walks over five frames to absorb the loss.
"It took a while to settle in there, so I was rushing quite a bit at the beginning," Maurer said.
Donaldson homered with one out in the second to give the A's the early edge before Barton doubled the lead with a two-out blast to right in the fourth.
Oakland added another two-out run in the fifth when Seth Smith kept the frame alive with a double and then scored on Lowrie's base hit to center.
Parker, meanwhile, held the Mariners hitless until the fifth, which started with a leadoff walk to Justin Smoak.
Ackley reached on a fielder's choice with one out before Shoppach launched a 3-2 fastball into the first row in right-center to bring the M's within a run.
With Maurer finished after five frames, Charlie Furbush took over to start the sixth and Moss greeted the Seattle reliever with a deep fly ball into the seats in right-center field to make it 4-2.
Parker issued consecutive one-out singles in the seventh to spell the end of his outing, as Sean Doolittle entered from the bullpen. Ackley then slapped Doolittle's fourth offering into right field to score Smoak and again bring the Mariners within one.
Ryan Cook worked out of a bases-loaded jam in the eighth by striking out Endy Chavez before Balfour shut the door in the ninth.
Balfour issued a walk to Shoppach around a pair of strikeouts before Michael Saunders smacked a single to left. Balfour escaped unscathed by grounding out Kyle Seager to end the contest.
Balfour has converted 24 consecutive save opportunities, with his last blown save coming on April 29, 2012 at Baltimore ... The A's improved to 3-6 on their 10-game road trip which wraps up with Sunday's matinee at Safeco Field ... Seattle went 1-for-6 with runners in scoring position and left eight men on base.