Joe Ortiz (2-0) pitched two innings for his second win in three days. Ortiz also earned the win Thursday in the opener of the four-game series. Joe Nathan pitched a perfect ninth for his fourth save in four chances.
Jason Bay had two hits and an RBI for the Mariners, who have lost four of five.
Mariners starter Joe Saunders remained unbeaten at Safeco Field with a no-decision despite a strong performance, allowing an unearned run on three hits in seven innings. In his 11 career starts at Seattle's stadium, Saunders is 7-0 with a 1.71 ERA.
Carter Capps (0-1) walked Craig Gentry to lead off the eighth and then got two outs before Andrus broke the 1-all tie with his hit to right field. Andrus then stole second and kept going to third when Capps' pitch went to the backstop, and scored on Beltre's single.
The Mariners had a scoring chance in the second when Justin Smoak singled and Kyle Seager walked to put runners on first and second with one out, but Texas starter Alexi Ogando, who gave up five hits and a run over five innings, got the next two outs to end the jam.
Seattle broke through in the fifth. Kelly Shoppach led off with a double down the left-field line that bounced over the outfield fence, and went to third on Dustin Ackley's single. With one out, Endy Chavez popped up to left, but it was too short for Shoppach to attempt to score.
Bay followed with a liner to center that hit Gentry's glove as he dove but the ball bounced off, allowing Shoppach to score the game's first run.
The Rangers tied it in the sixth inning, also taking advantage of a ball deflecting off a fielders' glove.
Nelson Cruz hit a low line drive to first baseman Smoak with the bases loaded and one out. The ball hit the heel of Smoak's glove and bounced out. Smoak grabbed it, threw to second for the force out and Ian Kinsler was caught between second and third. He was tagged out by third baseman Seager to complete the inning-ending double play, but not before Leury Garcia crossed the plate with the tying run.
NOTES: Seattle CF Franklin Gutierrez was out of the starting lineup for the second straight day. Mariners manager Eric Wedge said Gutierrez had tightness in his right groin but hoped the outfielder would return to the lineup Sunday. ... Rangers RHP Yu Darvish will have his next start pushed back to Friday against the Mariners in Texas, giving him two extra days of rest. LHP Derrick Holland, RHP Justin Grimm and RHP Alexi Ogando will be the starters for the Rangers' series at the Chicago Cubs starting Tuesday. ... RHP D.J. Mitchell cleared waivers and elected to become a free agent after he was designated for assignment by Seattle on Thursday.