SEATTLE -- Immediately after making contact, Seattle Mariners center fielder Leonys Martin turned toward the home dugout and barked out a celebratory howl as he flipped his bat.

And just like that, the Mariners' impressive start to the 2016 season had its signature moment.

"As soon as I hit the ball, I knew it was going to be gone," Martin said after hitting a 1-2 pitch 392 feet over the fence in right field for a two-run, walk-off home run that beat the Oakland A's 6-5 Tuesday night. "I crushed that ball."

Down to their final strike, the Mariners completed the ninth-inning comeback on Martin's two-run homer, snapping a five-game home losing streak. Martin hit a changeup from Oakland closer Ryan Madson (2-1) over the right field fence to score Norichika Aoki, who doubled down the line in the previous at-bat.

"We've had a few moments like that this year," first-year manager Scott Servais said, "but this was the biggest. We needed that."

Robinson Cano added a pair of hits and three RBIs for the Mariners (27-18), and Seth Smith singled in each of his three at-bats.

Mike Montgomery (2-0) earned the win after pitching 3 1/3 scoreless innings.

"A well-deserved win," Servais said of the left-handed reliever's performance.

Coco Crisp hit his fourth home run of the season and added a two-run double as part of Oakland's four-run sixth that established a 5-2 lead.

Cano hit a two-run homer in the eighth as Seattle rallied to within a run.

Crisp went 2-for-5 with three RBIs. Oakland designated hitter Khris Davis had two doubles and an RBI.

The A's, who broke open a close game with a four-run eighth inning Monday, used another big rally Tuesday to knock out Seattle starter Nathan Karns.

Karns allowed three runs on five hits over five-plus innings. He gave up back-to-back singles to open the sixth, and Nick Vincent came on with runners on the corners.

Davis tied the score 2-2 with a sacrifice fly to right, and Yonder Alonso singled to put runners on the corners. Marcus Semien's ground-rule double drove in a run to give the A's their first lead, 3-2. Crisp hit the bases-loaded double with two outs to put Oakland ahead 5-2.

After Seattle pinch hitter Franklin Gutierrez led off the bottom of the eighth with a double off the center field wall, Cano hit his 13th home run of the season off reliever John Axford to pull the Mariners within 5-4.

Axford took responsibility for the loss.

"This one's tough, it's hard," he said. "Our team put together a really good effort, offensively we did what we needed to do, then in that eighth inning, for me personally, that eighth inning was big. ... I just didn't do my job. I didn't get anyone out, I didn't do anything right, and that is what cost us there."

Oakland relievers Marc Rzepczynski and Fernando Rodriguez came on to hold the lead in the eighth, and Madson got the first two outs of the ninth before Aoki doubled down the left field line in front of a diving Crisp. Martin fell behind in the count before winning the game.

"Four changeups in a row, and the last one was pretty much right down the middle," Madson said. "That's the frustrating part. You make the fourth one the best one, and that's not what happened tonight."

Martin said of his ninth home run of the season, "An amazing feeling. For me, it's the best feeling I've had in baseball."

Middle-of-the-lineup hitters Cano and Nelson Cruz each drove in a run as the Mariners pulled out to a 2-1 lead after three innings.

Seattle jumped on top 1-0 on Cano's one-out, RBI double in the first. Cano followed a one-out single from Smith with a double into the left-center-field gap, bringing Smith around from first.

Crisp tied the score 1-1 with a solo homer in the top of the third for Oakland (20-27). It was Crisp's fourth home run of the season and his second at Safeco Field.

Cruz put Seattle back in front with a two-out, RBI single in the bottom of the third.

Oakland starter Kendall Graveman allowed two runs on seven hits over 4 1/3 innings, throwing 78 pitches. It marked the third time in Graveman's past six starts that he failed to get through the fifth inning.

NOTES: The A's named RHP Zach Neal as Wednesday's probable starter, although no roster move was made before Tuesday's game to officially recall him from Triple-A Nashville. Neal made his major league debut in a relief role earlier this season, allowing three runs over three innings in his lone outing. Neal will take the rotation spot of injured RHP Sonny Gray. ... Seattle SS Chris Taylor was back on the bench Tuesday, one day after being charged with two costly throwing errors in his first start of the season. ... Mariners CF Leonys Martin, who was swinging a hot bat, was back in the leadoff spot for a third consecutive game. ... The 13 players currently on Oakland's disabled list mark the most the franchise has had on the DL in at least 37 years. ... Seattle RHP Nathan Karns has not taken a loss since April 9. He has gone 4-0 with four no-decisions over his eight starts since then.