OAKLAND, Calif. -- The Oakland Athletics had lost a franchise-record eight straight times to the Seattle Mariners going into the finale of a three-game series on Wednesday at the Oakland Coliseum.

So, when Robinson Cano hit a two-run homer in the top of the eighth inning and the Mariners pulled even at 5-5, the A's had to be thinking, "Here we go again."

Not this time.

Mark Canha hit a solo walk-off home run with one out in the bottom of the ninth inning, powering the A's to a 6-5 victory in their final home game of the season.

Canha lined reliever Shae Simmons' 1-0 pitch over the left field fence for his fifth home run of the season and second career walk-off homer, both this season. Canha led off the bottom of the 10th inning with a solo shot to left on May 19 in a 3-2 victory against the Boston Red Sox.

"It was a lot of fun," Canha said. "Fun way to end it. It was a good day, definitely nice to have. I was having a rough series up until that point. Nice to cap it off like that for sure."

The walk-off homer was Oakland's eighth of the season, tied with the 1986 San Diego Padres for second most in major league history. The 1995 Cleveland Indians had a record nine.

Simmons (0-1) took the loss, while A's reliever Blake Treinen (3-4) got the win after pitching a scoreless ninth.

Matt Joyce had three doubles, tying the Oakland single-game record.

Nelson Cruz and Cano each hit two-run homers for the Mariners. Cruz hit his 38th home run in the fourth inning, and Cano hit his 23rd blast. Cano had two hits, two runs and two RBIs, while Cruz had two hits, one run and two RBIs. But this time, it wasn't enough to beat the A's.

"We had beaten them eight times in a row," Mariners manager Scott Servais said. "It's hard to keep that going. There are going to be some things that turn against you a little bit. Our guys today effort-wise, they certainly didn't give up."

The Mariners trailed 5-3 after seven innings, but Cano homered to left-center field off reliever Chris Hatcher in the eighth after Mitch Haniger's leadoff single.

Then in the top of the ninth, rookie catcher Mike Marjama blooped a double off Treinen with one out. Pinch runner Gordon Beckham tried to take third on Jacob Hannemann's ground ball, but shortstop Marcus Semien threw him out. The Mariners challenged the call, but after a review of 2:30, it stood.

"I clearly thought the hand got in there," Servais said. "Big play in the game."

A's right-hander Kendall Graveman allowed three runs on seven hits with four strikeouts and one walk over six innings in a no-decision. Graveman finished the season with a 5-0 record at the Coliseum in 11 starts. He joins Kenny Rogers as the only starting pitchers in Oakland history to go undefeated at home with at least five decisions. In 1998, Rogers went 11-0 in 17 starts at the Coliseum.

"It's good, to go undefeated at home," Graveman said. "For me, as long as the games that I start, we win, that's what I want."

Mariners right-hander Erasmo Ramirez gave up five runs (three earned) on eight hits over five innings with two strikeouts and two walks in a no-decision.

"I think I didn't execute pitches," Ramirez said. "The mix wasn't there at the right locations. I missed spots. I tried to go high and the ball stayed hip high. So they were able to get good contact."

The A's took a 1-0 lead in the first inning when Joyce blooped a double to left field and scored on Jed Lowrie's sharp single to right.

Oakland increased its lead to 2-0 in the third. Rookie second baseman Franklin Barreto lined a double to left-center field, advanced to third when center fielder Haniger booted the ball for an error and scored on Semien's sacrifice fly.

Seattle pulled even in the top of the fourth. Cano singled and Cruz hit a two-run laser, with an exit velocity of 117 mph, into the left field seats off Graveman.

"For us that get to watch him every day, it doesn't really surprise us anymore, how strong he is and when he does square a ball up how it jumps off the bat," Servais said. "When he hit the ball you think it's going to go foul, but it just didn't have time. It was hit that hard."

Oakland regained the lead with three runs in the fifth inning, two of them unearned. First baseman Ryon Healy hit a leadoff double and moved to third when Ramirez threw wildly to first for an error after knocking down Matt Chapman's comebacker.

Bruce Maxwell lined an RBI single to center, Canha hit a sacrifice fly and Joyce roped a run-scoring double to right.

Seattle cut Oakland's lead to 5-3 in the fifth inning on Ben Gamel's RBI single.

NOTES: Mariners OF Guillermo Heredia is expected to undergo surgery on his sore right shoulder after getting a second opinion, Mariners manager Scott Servais said Wednesday. Heredia, who returned to Seattle from Oakland, hasn't played since Sunday against Cleveland. ... Mariners C Mike Marjama made his first major league start and went 2-for-4 with his first two major league hits, a fifth-inning single and a double in the ninth. He also threw out A's 3B Matt Chapman trying to steal second in the fifth. ... A's LF Khris Davis hit 26 of his 42 home runs this season at the Coliseum, and finished one shy of tying Jason Giambi's record of 27 set in 2001.