OAKLAND -- Mark Canha hit a game-ending home run in the ninth inning to lead the Oakland Athletics past the Seattle Mariners 6-5 on Wednesday.
Canha's fifth homer this season came on a 1-0 pitch from Shae Simmons (0-1).
Oakland avoided a three-game sweep and snapped an eight-game losing streak against Seattle.
The A's improved to 15-10 in September, clinching their first winning month since April of 2016. They won 15 games in a month for the first time since June 2015.
Matt Joyce tied an A's record with three doubles.
Blake Treinen (3-4) pitched a scoreless ninth, working around a one-out double by rookie Mike Marjama.
Cano's 23rd homer was Seattle's second game-tying home run on the day. The Mariners trailed 2-0 when Nelson Cruz hit his team-leading 38th homer, a two-run shot off Kendall Graveman in the top of the fourth.
Graveman left the game with a 5-3 lead and was in line to win his fourth straight decision. Oakland's ace struck out four and gave up three runs on seven hits and one walk in six innings.
PROTESTING IN TEXAS
Asked whether he has concerns about catcher Bruce Maxwell taking a knee during the national anthem to protest racial injustice in this weekend's road series against the Rangers, A's manager Bob Melvin said he'll have a better sense of the atmosphere once his team gets to Texas.
"I don't think it'll bother him, put it that way," Melvin said. "He's pretty committed to what he's doing and continues to do so and he'll do it in Texas."
Marjama made his first career start. The 28-year-old was 2 for 4, collecting his first major league hits.
Mariners: OF Guillermo Heredia left the team and is expected to have surgery to repair a right shoulder injury he's been playing with all year. Heredia, who bats and throws left-handed, will get a second opinion before having the procedure performed by a specialist in Miami, manager Scott Servais said.
Mariners: LHP Marco Gonzales (1-1, 5.51 ERA) will pitch Friday's series opener against the Angels in Los Angeles. The 24-year-old rookie is 1-0 with a 2.25 ERA in his last four starts.
Athletics: LHP Sean Manaea (11-10, 4.56) will pitch Thursday's series opener in Texas. Manaea missed his last start with upper back tightness. The 25-year-old is 1-1 with a 6.10 ERA in six career starts against the Rangers.