Updated

Houston, TX (SportsNetwork.com) - Jeff Samardzija pitched eight strong innings and the Oakland Athletics took an 8-2 win over the Houston Astros in the opener of a three-game series.

Samardzija (4-3) allowed two runs on six hits and a walk while striking out 10 batters for the A's, who have won three of their last four.

"I was going pitch-to-pitch and not letting the previous things affect the future things," said Samardzija. "I wanted to be aggressive and I knew I had a good fastball warming up so I wanted to be aggressive with it."

Josh Donaldson went 3-for-4 with three RBI while Josh Reddick hit a two-run home run. Derek Norris drove in two runs for Oakland, which moved into a tie for first place in the AL West with Anaheim after the Angels lost to the Marlins on Monday.

Chris Carter hit a two-run home run for the Astros, who have dropped four of their last five games. Scott Feldman (7-10) allowed three runs on seven hits over seven innings to take the loss.

"Scotty threw the ball well," said Houston manager Bo Porter about Feldman. "He gave up that one home run, but aside from there he threw it really well out there tonight."

The A's pushed one across in the third inning on an RBI double from Donaldson that scored Alberto Callaspo, who had reached base on a fielder's choice.

In the fourth, Brandon Moss singled with one out and Reddick followed with a blast over the right field wall for his 10th home run and a 3-0 lead.

Samardzija stymied the Astros through the first seven innings as he didn't allow a runner past second base, but he got into trouble in the eighth.

After the first two batters struck out, Jose Altuve kept the inning alive with a single. Carter followed with his 31st home run of the season to cut the deficit to one.

The A's, though, busted the game open in the ninth as they started the inning with four straight walks against Tony Sipp to force in one run. Two batters later, Donaldson, facing Jose Veras, doubled in two more runs. Norris contributed a two-run single for an 8-2 lead.

Game Notes

The Athletics placed catcher John Jaso on the seven-day concussion list, retroactive to August 24, on Monday ... Marwin Gonzales went 3-for-4 with a pair of doubles for Houston ... Oakland went 3-for-10 with runners in scoring position.