OAKLAND, Calif. -- Right-hander Hisashi Iwakuma got back on track, and the Seattle Mariners gained more ground in the American League wild-card playoff race on Friday night at the Oakland Coliseum.

Iwakuma pitched 6 2/3 strong innings for his career-high-tying 15th victory, a 3-2 win against the Oakland A's.

The Mariners (73-68) won their third straight game and moved to within 3 1/2 games of Detroit and Baltimore for the second wild-card playoff spot.

"We all fight and play to play in the playoffs," Iwakuma said. "As a starter, I only pitch one game every five days. Being that day today, you want to go out and give it all you got, and I was able to do that."

Iwakuma (15-11) ended his career-high-tying four-game losing streak and had his fourth quality start in his past five outings. He allowed two runs on seven hits, struck out five and walked one, winning for the first time since Aug. 13 at Oakland.

"That's his best start in a while, just command wise," said catcher Mike Zunino, who hit a solo home run in the seventh inning. "His stuff was great. I thought he had great command of his slider tonight. He was able to back-door to lefties and throw it in on them. Split was really good, and I think he just worked ahead of guys, which was key."

Norichika Aoki had a solo homer in the third inning for the Mariners, who struck out 12 times. Nelson Cruz, who entered the game hitting .404 with four extra-base hits against Oakland this season, had an RBI double in the first.

"I really believe in our team," Mariners manager Scott Servais said. "We just got to keep winning series and hopefully run into one, we sweep one here or there and see where we're at. I'd love to get back home and be in a really good spot and make those games really exciting. That's what we're shooting for."

A's rookie right-hander Daniel Mengden (1-7) allowed two runs on five hits over five innings and exited trailing 2-1. Mengden struck out six and walked two in his best outing since June 27, when he held the Giants to two runs over 7 2/3 innings for his only win of the season. Mengden fell to 0-6 at the Coliseum and set an Oakland record for the longest career-opening home losing streak.

"The last couple outings haven't been good so I think this was a big step forward," Mengden said.

Rookie catcher Bruce Maxwell had a career-high three hits in three at-bats with an RBI double for the A's. Rookie second baseman Joey Wendle, leading off for the first time in his major league career, went 2-for-4 and drove in a run. But throughout most of the game, Iwakuma had his way as he improved to 4-0 this season against the A's.

"That's what we've seen out of him basically all year," A's manager Bob Melvin said. "Just when you feel like you have a bead on him and you're going to score some runs off him, he makes big pitches when he has to. "

The Mariners held a 2-1 lead through six innings, but Zunino made it 3-1 with a leadoff blast to center field in the seventh off reliever Daniel Coulombe. Zunino launched Coulombe's 1-1 fastball for his 10th home run of the season.

Oakland answered with a run in the bottom half when Max Muncy walked with one out and Maxwell brought him home with a two-out double to center, ending Iwakuma's night.

Dan Altavilla came on to get the third out in the seventh. Steve Cishek pitched a perfect eighth with two strikeouts, and Edwin Diaz a 1-2-3 ninth for his 14th save.

"We got off to a pretty quick start then we kind of faded offensively," Servais said. "So we certainly needed pitching tonight and everybody stepped up. It was nice to see."

The Mariners took a 1-0 lead in the first inning when Robinson Cano worked a two-out walk and scored on Cruz's double off the right-center field wall.

Aoki extended Seattle's lead to 2-0 with a leadoff homer in the third. Aoki launched Mengden's first-pitch fastball over the wall in right center for his second home run of the season.

Oakland cut Seattle's lead to 2-1 in the fifth. Muncy blooped a single with one out, Maxwell grounded an opposite-field single to left with two outs, and Wendle grounded an RBI single to center.

NOTES: A's RHP Fernando Rodriguez had right shoulder surgery to repair two torn tendons Friday in Chicago. Rodriguez had been on the 15-day disabled list since July 4 with a strained right shoulder. He is expected to be able to resume throwing in four months. ... Mariners RHP Tom Wilhelmsen (lower-back spasms) is expected to be activated from the disabled list Saturday, manager Scott Servais said Friday. Wilhelmsen has been on the 15-day DL since Aug. 27. ... Mariners C Steve Clevenger, who has been on the disabled list since June 30 with a fractured metacarpal bone in his right hand, has been shut down because of soreness in his right elbow. ... A's LHP Sean Manaea (strained upper back), who hasn't made a start since Aug. 29, will pitch a three-inning bullpen session Saturday. If all goes well, he's expected to return to the rotation during the A's upcoming seven-game road trip, which begins Monday at Kansas City.