OAKLAND, Calif. -- Jeff Samardzija made sure that his homecoming Sunday turned out to be one worth celebrating.

The White Sox right-hander allowed three runs over eight innings, and Chicago defeated the Oakland A's 7-3 at the O.co Coliseum, sweeping the three-game series and winning its season-high fifth consecutive game.

Samardzija (3-2) allowed eight hits, struck out five and walked three in his first career appearance against the A's, who traded him to the White Sox on Dec. 9 as part of a six-player deal. Samardzija went 5-6 with a 3.14 ERA in 16 starts for Oakland last season after being acquired on July 5 from the Chicago Cubs.

"I have the utmost respect for those guys over there," said Samardzija, who threw 120 pitches. "I've never seen a team play so hard every day out. They come to play, they're professionals, and I loved being a part of it, so I knew I had to come in and have good stuff today and they were going to come at me. They swung at my heater early, and I had to make some adjustments. They played hard, as I expected."

Right fielder Avisail Garcia went 3-for-5 with a two-run homer in the ninth for the White Sox (17-17), who reached the .500 mark for the first time this season and swept the A's in Oakland for the first time since 1997. First baseman Jose Abreu went 1-for-4 and extended his hitting streak to 12 games. He drove in a run and scored once. Shortstop Alexei Ramirez added two hits and two RBIs.

"I think we're tremendously talented," Garcia said. "Everyone's pretty much healthy. It's still a young season, but we have veteran talent and we have young talent. We're a really focused team, whether we win or whether we lose."

Samardzija pitched his way out of a bases-loaded jam in the first inning and didn't give up any runs until the fourth, when A's rookie first baseman Max Muncy hit his first career home run, a two-run shot.

"Jeff was sharp," White Sox manager Robin Ventura said. "He gave up a couple there but battled. I know it was a high pitch count, but he just seems to get a little bit better the deeper he goes in the games and the more pitches he throws. That's the reason for giving him the eighth."

Oakland left-hander Scott Kazmir (2-2) allowed five runs (three earned) on seven hits while lasting only 4 1/3 innings, his shortest outing of the season. Kazmir struck out six, walked three and was hurt by three errors, including one of his own.

The A's lost their fourth straight game and fell for the 10th time in their past 11 games. They committed four errors overall -- two by shortstop Marcus Semien -- and they lead the major leagues with 42 for the season. Oakland committed at least one error for the 14th game in a row, and Semien has made 13 errors this year.

"It's just snowballing on us right now," A's manager Bob Melvin said. "Guys are thinking about it out there. They don't want to make an error, and they end up doing it. We're not playing clean games at this point. They are ugly games, and it affects how you play them. It affects your confidence."

Oakland (13-26) owns the major leagues' worst record.

The White Sox grabbed a 1-0 lead in the top of the first inning, taking advantage of center fielder Adam Eaton's leadoff double and errors on Kazmir and catcher Stephen Vogt to score an unearned run.

Oakland answered with two runs in the fifth. Left fielder Coco Crisp walked with one out, and Muncy hit a two-run shot off Samardzija with two outs. Samardzija got ahead 0-2 in the count, but Muncy hit his 95 mph fastball over the right-center-field fence.

"That was a special moment," Muncy said. "Unfortunately, we couldn't get the win, but it's something I'll never forget."

Chicago scored four times in the top of the fifth, taking a 5-2 lead. Leading off, Eaton hit a hard one-hopper to Semien, who booted the ball for an error. Designated hitter Emilio Bonifacio singled to left, moving Eaton to second.

With one out and runners on first and third, Abreu grounded a sharp single down the third base line, driving in Eaton. Garcia loaded the bases with an infield single, and third baseman Gordon Beckham walked, forcing Cabrera home to make it 3-2. Ramirez then hit a hard ground ball that was headed for Semien but ricocheted off Kazmir's glove and into left field for a two-run single.

That was it for Kazmir, who gave way to right-hander Dan Otero.

"I wish I could have been a little more efficient early on and made a couple plays," Kazmir said. "It would have been a totally different ballgame. We feel like we're on the verge of making stuff happen. We're going through a tough stretch right now."

The A's cut Chicago's lead to 5-3 with a run in the bottom of the fifth. Center fielder Billy Burns hit a leadoff single, stole second, moved to third on right fielder Josh Reddick's infield single and scored on designated hitter Billy Butler's ground ball.

Avisail made it 7-3 in the ninth with his fourth homer of the season, a two-run shot to right-center with two outs off right-hander Tyler Clippard. Left fielder Melky Cabrera was on base after a one-out single.

"Some teams might focus a little bit on Jose," Ventura said. "Not that you forget about Avi, but he's lurking there, and he swings the bat real nice, has a nice approach, inside out. When he gets it, it's going to go."

NOTES: The A's placed 1B Ike Davis (strained left quadriceps) on the 15-day disabled list retroactive to Thursday. Davis had an MRI exam Saturday that revealed a Grade 2 strain. .. Oakland recalled OF Craig Gentry from Triple-A Nashville. Gentry was hitting .086 with the A's before being sent down on May 6. He hit .171 with no extra-base hits in nine games with Nashville. ... White Sox INF Emilio Bonifacio, a switch hitter, made his sixth start of the season and first at designated hitter, as regular DH Adam LaRoche was out of the lineup against A's LHP Scott Kazmir. ... The White Sox, who went 5-1 on their road trip, open a seven-game homestand Monday against the Cleveland Indians. They have won all five of their home series this season and are 10-5 at U.S. Cellular Field.