Oakland, CA (SportsNetwork.com) - Chris Carter hit a two-run homer and drove in three runs to help the visiting Houston Astros beat the slumping Oakland Athletics 4-3.

Jose Altuve had two hits with two runs scored and Jon Singleton added a solo homer for the Astros, winners of five straight.

The A's, meanwhile, have dropped three games in a row and seven of eight overall. They now trail the AL West-leading Angels by six games and are only two games ahead of Seattle for the AL's first wild-card spot. Detroit is a half-game behind the Mariners.

Oakland starter Jeff Samardzija (4-5) retired the first seven batters before Singleton homered to right-center field.

The A's scored three runs in the bottom of the third after loading the bases with one out against Houston starter Brett Oberholtzer (5-10). Derek Norris tied the game with an RBI single, and a second runner scored on Jake Marisnick's fielding error. Adam Dunn later supplied a run-producing single.

Oakland had a chance again with the bases loaded, this time with no outs, in the fourth and Oberholtzer managed to escape the jam. Craig Gentry hit a grounder to third baseman Matt Dominguez and he threw home for the force out. Josh Donaldson then grounded into an inning-ending double play.

The Astros grabbed the lead in the sixth. Carter, who singled home Altuve in the fourth, plated him again with a two-out drive to left-center field.

Tony Sipp tossed the final two innings to earn his third save.