The Mariners were within one pitch of winning their second straight to open the AL West showdown series with front-running Texas, but Prince Fielder's solo homer off Seattle closer Steve Cishek on a full count with two outs in the ninth tied it 1-1.
The Rangers then went on to a 2-1 victory on Rougned Odor's home run in the 11th inning. Seattle, which was swept three games last weekend in Texas, could have pulled within two games of the Rangers with a win.
Cishek, who also gave up a solo homer Friday night en route to a four-out save, said he was trying to go up and in on Fielder, who entered hitting .194 with just four home runs.
"I know he's been struggling this year, but I know he also has good power," Cishek said. "I just got a little arrogant and tried to stick one in there on him and it cost us the game."
In the bottom of the 10th, the Mariners loaded the bases with two outs, but Ketel Marte's drive to right was hauled in on the warning track.
After Odor's home run, reliever Steve Johnson stranded two on base to keep the game close.
In the bottom of the 11th inning, Norichika Aoki was hit by a pitch to open the inning, but then was forced at second on Shawn O'Malley's bunt. The Mariners challenged the play at second, but the call was confirmed.
"It was a bang-bang play at second, but at the end of the day, we just didn't get the big hit," manager Scott Servais said. "We certainly had chances late. We put some rallies out there."
Jim Hoehn is a contributor for MLB.com based in Seattle.