OAKLAND -- Scott Kazmir pitched seven innings to win his fourth straight start, Yoenis Cespedes hit his 14th home run of the season and the A's beat the Boston Red Sox 4-2 on Thursday night at O.Co Coliseum.
Stephen Vogt had two hits and two RBIs, Jed Lowrie scored twice and John Jaso singled in an insurance run in the seventh to move the A's a season-high 17 games over .500. It's the best record in the majors and continued Oakland's best start since 1990.
Kazmir (9-2) went into the game with the second-lowest ERA among qualifiers in the AL and extended his streak to 18¹/³ innings without allowing an earned run before Dustin Pedroia hit a two-run home run in the sixth. He struck out eight and didn't walk a batter.
Cespedes had not homered against the Red Sox until his two-out, solo shot off Jake Peavey in the third.
Boston had played five straight one-run games heading into the series opener with Oakland. This one was tight as well.
The A's led 3-0 after Vogt's single scored Lowrie in the fourth.
Kazmir, who hasn't lost since May 23, took a shutout into the sixth that Pedroia ended with a two-out home run.
It was the only mistake Kazmir made. Over his past five starts, Oakland's right-hander is 4-0 with a 1.27 ERA.
Luke Gregerson pitched the eighth and Dan Otero worked the ninth for his first career save.
Peavey (1-5) had a second straight strong outing but remained winless over his past 10 starts. Peavey allowed five hits over 6¹/³ innings, retired eight of the final nine batters he faced and struck out four with three walks.
It wasn't enough to prevent the Red Sox from ending their three-game winning streak.
Vogt hit an RBI groundout off Peavey in the second and singled in another run in the fourth. Lowrie, who walked and doubled, scored both times.
Cespedes hit his 14th home run with two outs in the third. The Cuban slugger is batting .343 with four home runs and 12 RBIs through 17 games in June.
Kazmir retired 15 of the first 17 batters he faced before Pedroia's two-run home run cut Oakland's lead to 3-2.
NOTES: Otero was in the closer's role because Sean Doolittle had pitched in the previous two games. ... Cespedes has now homered against every team in the AL except Tampa Bay. ...RHP Clay Buchholz (hyperextended knee) pitched six scoreless innings during his second rehab start for Triple-A Pawtucket. ... LHP Brad Mills starts Friday in his Oakland debut. Mills was acquired in a trade from Milwaukee earlier this week. LHP Felix Doubront (2-4) pitches for Boston.