The Rangers won their third in a row and have captured 11 of their last 13 contests.
Texas overcame a 4-2 deficit with a four-run fifth, highlighted by David Murphy's two-run single. Murphy has six hits and seven RBI over his last two games.
With the Rangers clinging to a one-run lead heading into the ninth, Nathan retired the first batter of the inning.
Josh Reddick then drew a four-pitch walk, went to second on a wild pitch and stopped at third when Yoenis Cespedes singled to right.
Nathan survived the trouble, however, striking out Seth Smith and getting Brandon Inge on a grounder to shortstop. It was Nathan's 18th save.
Scott Feldman (2-6) was credited the win after a struggling, five-inning performance. He gave up four runs on nine hits.
Tyson Ross (2-8) surrendered five runs on eight hits in four frames to take the loss.
Josh Reddick, Derek Norris and Cliff Pennington all hit solo homers for the A's.
Celebrity Families of 2014 [PHOTOS]