Texas and the Los Angeles Angels are 2 1/2 games behind Minnesota for the second wild card. The Angels lost to Cleveland, while the Twins blew out Detroit.
Hamels (11-4) allowed three hits and a run while striking out eight. He gave up a solo homer to Nelson Cruz — his 35th — in the seventh, along with a pair of singles to Jean Segura.
Hamels has a 29-16 career record in September and October, including 8-3 in three seasons with Texas.
"That’s veteran leadership showing up," Rangers manager Jeff Banister said. "That’s knowing how to go out and perform and put your team in a winning situation. We’ve seen it so many times before from him."
Keone Kela got his second save despite yielding a solo homer to Robinson Cano in the ninth. It was Cano’s 22nd this season and 300th of his career.
"It means a lot," Cano said. "In a humble way, it’s something that makes me proud of myself, proud of my family and the way they raised me to help me get to this level."
The Mariners have lost five straight games and are five back in the wild-card chase with nine games remaining.
James Paxton (12-5) allowed two runs in 3 2/3 choppy innings. The hard-throwing left-hander was making his second start since a pectoral injury landed him on the disabled list, and he’s struggled both times.
"I was moving the fastball around better, breaking stuff was sharper," Paxton said. "Not as sharp as I can be, but it’s definitely a step in the right direction. Tonight, unfortunately, it wasn’t enough."
Carlos Gomez had a two-run double in the first that caromed off the glove of Seattle third baseman Kyle Seager.
"It’s important for us to finish strong," said Gomez, now in his 11th big-league season. "We showed the young guys that this is going to be tough but we never give up."
Beltre hit his 17th home run in the sixth and Choo hit his 20th in the seventh. For Beltre, that tied him with Jose Canseco, Adam Dunn and Detroit’s Miguel Cabrera for 35th on the career home run list with 462.
SAFE AT HOME
Mariners closer Edwin Diaz, whose home island of Puerto Rico has been battered by Hurricanes Irma and Maria, finally heard from his family Wednesday. His cousin called and said the damage was minimal. "Nothing bad. I’m happy for that," he said, although he doesn’t know the status of his house or his grandmother’s house.
Diaz has been anxious but said he has to block it out. "The game is one part and my family is another part," he said. "When I’m in the game, I have to do my work. I think about them, but I have to concentrate 100 per cent on what I do."
Rangers: Gomez started in centre field after missing most of 10 games with a right ankle sprain. He did appear in one game, Tuesday, as a pinch hitter.
Mariners: RHP Dan Altavilla, rested the past couple games with a bruised foot, entered with two outs in the fourth inning.
Rangers: RHP Nick Martinez (3-6, 5.47) goes into the Oakland Coliseum, where he has a 1.77 ERA in seven appearances, ninth lowest ever there (min: 35 innings). He’ll be opposed by A’s RHP Kendall Graveman (5-4, 4.39).
Mariners: RHP Erasmo Ramirez (5-6, 4.56), re-acquired in a July 28 trade with Tampa Bay, makes his 10th appearance with Seattle. Since arriving, he is 1-3 with a 4.22 ERA. The Indians will start RHP Trevor Bauer (16-9, 4.41).