"Blake was up tonight. They hit a lot of balls hard, a lot of hard outs," Wedge said. "I didn't feel like we could take him any further. He was just kind of living on the edge there."
Seven of Beavan's 14 outs came on well-hit balls to the outfield, but the one that hurt was Drew's two-run blow over the right-field fence in the third.
"I should have been smarter on my part," said Beavan. "He's a veteran hitter and he's going to try and jump on that first pitch if he sees something he can hit. And I pretty much put it on a tee for him."
Beavan's record fell to 10-11 with a 4.68 ERA, but he's 7-5 with a 3.73 ERA in 13 starts since his midseason recall. The 23-year-old has one start remaining as he'll go in the season finale on Wednesday afternoon against the Angels at Safeco Field.
The A's then broke things open with four runs off relievers Charlie Furbush and Stephen Pryor in the seventh, helped by three walks, an infield single and a throwing error by Dustin Ackley.
Furbush didn't record an out while walking two batters and giving up a single while throwing just five strikes in 14 pitches. He wound up charged with three of the four runs in a rare stumble this season.
"He didn't look like his normal self out there," said Wedge. "He's been so good for us and so aggressive, using all his pitches and being good against left-handers and right-handers. But tonight, for whatever reason, he just wasn't himself."
The Mariners defense didn't help any as Ackley yanked his throw wide of Jaso trying to get the out at home on a bases-loaded grounder by Josh Reddick off Pryor with one out. Josh Donaldson then followed with a two-run single to put the game away.
"That's something I've struggled with," Ackley said. "That's a play that isn't really worked on that much and it's showing for me right now because I've made bad throws in that situation. It's just something I need to work on more and improve on."
Oakland upped its record to 89-68 and maintained its two-game lead over the Angels for the second AL Wild Card spot with just five games remaining.
The Mariners dropped to 73-84 overall and 7-10 against the A's this season with two games remaining in Oakland this weekend before the season wraps up with three against the Angels in Seattle.
Right-hander A.J. Griffin, one of five rookie starters in the A's rotation, improved to 7-1 by holding the Mariners to one run on four hits in 5 2/3 innings while lowering his ERA to 2.71.
Seattle's only run against the 24-year-old came on a solo home run to center by Trayvon Robinson in the second.
"He's got good stuff, a good fastball, good off-speed stuff," said Robinson, who faced Griffin earlier this season in Triple-A. "He keeps you honest. He just left that one curveball up and I was trying to drive something and got it out."
It was Robinson's third home run of the year and extended the Mariners' streak of hitting at least one home run to 17 straight games, the second-longest run in franchise history and two games shy of the record 19 set in 1999.
Michael Saunders added Seattle's second run on a solo shot leading off the seventh against reliever Sean Doolittle for his 18th home run of the year, tying him with Kyle Seager and moving him one back of Justin Smoak's team lead.
The Mariners had a chance to do some damage in the sixth when it was still a 4-1 game, loading the bases with two outs and ending Griffin's night, but Doolittle got Smoak to fly out to right field to end that threat.
Seattle wound up 0-for-7 with runners in scoring position and is now 4-for-64 (.063) over its last eight games in those situations.