OAKLAND, Calif. — Even with a four-run deficit, Nelson Cruz hollered through the dugout some words of confidence.

“I was screaming, ‘We got it, we’re going to win it!’”

A big swing by Cruz and a two more from Dae-Ho Lee helped Cruz make good on that bold declaration, and Seattle is starting May with some serious swagger atop the AL West.

Lee hit a go-ahead two-run homer in the seventh after an earlier solo shot for his first career multi-homer game, and the Mariners rallied for a back-and-forth 9-8 win over the Oakland Athletics on Wednesday and their first 2016 series sweep.

Mike Montgomery (1-0) pitched two scoreless innings for the win on a day Cruz sent a rare shot into the second deck of seats in dead-center.

“Just another homer,” cracked Cruz with a grin. “I was kind of surprised.”

The hit left Felix Hernandez shaking his head.

“He crushed that one,” Hernandez said. “He said he’s still got more in the tank.”

Lee hit his third and fourth homers, connecting in the seventh against Axford (2-1) as the Mariners had a season-high 16 hits and improved to an AL-best 11-4 on the road. The A’s lost their fourth straight.

Coach Edgar Martinez offered a little of his hitting expertise to Lee complete with John Axford’s tendencies.

“Those are the kind of wins that stick with you for a while,” first-year Mariners manager Scott Servais said.

Sean Manaea was denied his first career win despite Oakland getting to nemesis Hernandez on consecutive fifth-inning errors, while Hernandez had seemed poised to become the winningest pitcher in Mariners franchise history with victory No. 146.

One error came when the ace fumbled Josh Reddick’s dribbler with a chance to throw out the tying run at home. Khris Davis’ grounder got past third baseman Kyle Seager moments later as the A’s scored two more for a 6-4 lead, and Hernandez’s day was done.

Cruz connected for a two-run drive to highlight Seattle’s four-run fifth against the rookie left-hander Manaea, making his second big league start.

But that lead was short-lived as the A’s came back for an 8-4 advantage they would then squander.

Hernandez matched his shortest outing against Oakland of four innings on May 16, 2006. The bullpen delivered.

“I should have made that play, that groundball. That was a weird inning,” Hernandez said. “The offense, they got my back, they picked me up today. The bullpen was really good, too. That was awesome. That was a great win for us.”

Joel Peralta struck out two in the eighth, and Steve Cishek earned his eighth save in as many tries.

Marcus Semien hit his team-leading seventh home run in the third off Hernandez to put the A’s ahead, and Billy Butler drove in two runs including a run-scoring single in the fifth. Butler made his first start at designated hitter in a week and only his ninth in the first 29 games.

“We finally get some hits, some good swings, make him work, get some runs off him and kind of let him off the hook,” A’s manager Bob Melvin said. “So disappointing.”

Manaea hung tough after Cruz’s big blast while opposing one of baseball’s best pitchers. The lefty, who made his major league debut last Friday against Houston after only 42 appearances in the minors, allowed four runs, all earned, on seven hits in five innings, struck out six and walked one.

He punched his pitching hand into his glove in celebration after retiring Norichika Aoki on a groundout to end the third. Aoki hit an infield single in the fifth and has hit safely in his last 15 games against Oakland.

Ketel Marte followed with an RBI double before Robinson Cano’s RBI single.

Aoki added a sacrifice fly in the sixth. Seattle is 8-0 in the last eight one-run games at the Coliseum.

Sean Doolittle hadn’t allowed a run over his previous eight games and 6 1/3 innings before surrendering two runs in two-third of an inning.

Hernandez is 11-3 at the Coliseum, one win shy of Tommy John for most career victories by a visiting pitcher in Oakland.

TRAINER’S ROOM

Mariners: RHP Tony Zych, placed on the 15-day DL with tendinitis in his rotator cuff, flew to Seattle on Tuesday to be seen by a doctor but Servais didn’t have an immediate update.

Athletics: OF Coco Crisp left the ballpark to be seen by a doctor for a non-baseball medical issue. He’s also dealing with a heel injury that would have kept him out of the lineup for the series finale with an off day Thursday.

UP NEXT

Mariners: LHP Wade Miley (2-2, 5.06 ERA), coming off his first career shutout in a five-hitter against Kansas City, takes the mound at Houston on Thursday night.

Athletics: LHP Rich Hill (3-3) starts at Baltimore on Friday looking to stay unbeaten on the road. He is 3-0 with 0.95 ERA away from the Coliseum.