The A's had only two hits through the first 8 1/3 innings against Texas, which fell 4 1/2 games behind the Angels in the AL West.
Mike Wuertz (6-1) pitched 1 1/3 innings to get the victory after Brett Anderson gave up six hits over 7 2/3 innings with eight strikeouts and three walks.
Hank Blalock scored the game's first run on a double play in the fifth inning and Marlon Byrd added a run-scoring single in the eighth to give the Rangers a 2-0 lead.
Texas starter Dustin Nippert gave up a hit in five innings. Four relievers combined for 3 1/3 scoreless innings before Wilson came on in the ninth.