Josh Donaldson hit a pair of two-run homers to help the A's cruise to a 10-1 win over the Houston Astros on Thursday night.
It was the first career multihomer game for Donaldson, who connected in the first inning and pushed the lead to 10-1 with a second shot in the seventh.
Alberto Callaspo added a two-run homer in the third and Jed Lowrie had three hits for the A's, who improved to 24-5 against Houston, which joined the American League West before the start of last season.
Scott Kazmir is off to a 3-0 start for the first time in his career after allowing five hits and a run with seven strikeouts in six innings. He lowered his ERA to 1.62.
The A's jumped on Houston starter Brett Oberholtzer (0-4) early and tagged him for a career-high six runs on and eight hits, which tied a career-high, in just 3²/³ innings.
Houston's only run came on a bases-loaded walk in the first inning and they had trouble stringing any hits together. They had a terrible night on defense, committing five errors after entering the night leading the majors with a .992 fielding percentage and just seven errors.
The Astros were swept by the A's in a three-game series in Oakland last week and there still seemed to be some animosity between the teams from an 11-3 loss in the first game of that series.
In that game, Houston reliever Paul Clemens appeared to try to hit Lowrie with a pitch in the third inning after Lowrie had attempted a bunt in the first with Oakland up by seven runs. Afterward, Houston manager Bo Porter came out of the dugout to scream at Lowrie after he hit a fly out after two inside pitches.
On Thursday night, Clemens was ejected after hitting Lowrie on the backside with the first pitch of the at-bat with Oakland leading 8-1. Donaldson hit his second home run after the plunking.
Donaldson's towering 389-foot homer, which clanged high off the foul pole in left field, gave Oakland a 2-0 lead in the first inning. Houston cut it to 2-1 when Chris Carter drew a bases-loaded walk in the bottom of the inning.
The trouble continued for Oberholtzer in the second inning when Craig Gentry doubled with one out. He then plunked Brandon Moss before a two-out RBI bloop single by Coco Crisp. Crisp advanced to second on an error by George Springer on the play.
Donaldson hit a leadoff double in the third and scored on a single by Derek Norris with one out to make it 4-1. Callaspo followed with his two-run home run to the Crawford Boxes in left field to push the lead to 6-1.
Gentry ended up on second base after a fielding error and a throwing error by Matt Dominguez on the same play.
Moss added an RBI single in the fifth inning and Lowrie had a run-scoring double later in the inning to push the lead to 8-1.
NOTES: A's' RHP Jesse Chavez opposes RHP Brad Peacock in the second game of the series on Friday night. ... Oakland RHP A.J. Griffin, sidelined since the start of the season with an elbow injury, will visit Dr. Thomas Mehlhoff in Houston on Tuesday for a second opinion. ... Houston reliever Matt Albers wasn't available for a third straight game on Thursday because of tightness in his right shoulder. Porter said he doesn't think the problem is serious.