Continued home success against the Boston Red Sox has also helped the Oakland Athletics remain tough to beat at the Coliseum.
The A's can record a fifth straight home victory overall and against the Red Sox on Saturday.
Coco Crisp delivered a two-out single in the eighth inning to help Oakland (46-28) improve to 6-2 on a 10-game homestand with Friday's 4-3 win over Boston. Josh Donaldson hit a three-run homer for the major league-leading A's, who have won 17 of 22 at the Coliseum, where they are 23-14.
"We'll see what happens,'' Crisp said. "It's a long season. I'm not saying that we are or are not the best team in baseball. That's a tough question to answer.''
Oakland has won 10 of 11 and 20 of 25 at home against the Red Sox (34-40), who last won a series there April 1-2, 2008.
Crisp, who won a World Series with Boston in 2007, is batting .366 with 12 RBIs during his last 19 home games.
Donaldson is hitting .318 (7 for 22) in his past six games after going 0 for 29 in his previous seven contests.
The A's get their first look at Boston's Rubby De La Rosa (2-2, 2.84 ERA), who has allowed five hits over 14 scoreless innings to go 2-0 at home since making his season debut May 31. However, he's been reached for eight runs and 16 hits in 11 1-3 innings to lose both road starts. The right-hander hopes to turn things around away from Fenway Park, where he gave up one hit in seven innings of a 1-0 home victory over Minnesota on Monday.
"When a guy possess that type of arm and that repertoire, as long as he throws strikes, he's going to have the ability to get some of the best hitters in the game," manager John Farrell said.
Alberto Callaspo is the only Oakland hitter to face De La Rosa, going 0 for 2 with a walk and a strikeout.
David Ortiz and Mike Napoli each had two hits Friday for the Red Sox, who dropped the first two of this set after sweeping a three-game home series from the Twins. Boston scored more than two runs for this first time in seven games, a stretch in which six have been decided by one run.
''We're right there," Boston's Jonny Gomes said.
Napoli is 6 for 17 (.353) in his last five games at Oakland, and 2 for 5 with a triple and a home run versus scheduled starter Jesse Chavez (6-4, 2.93).
The right-hander has pitched six innings in four straight starts and allowed three earned runs while splitting the last two. He gave up one run in a 10-5 win over the New York Yankees on Sunday.
"It's not like he was pitching poorly, but (that was) the type of outing we were seeing earlier in the year when he was really knifing through teams and cutting through them very quickly," manager Bob Melvin told the Athletics' official website.
This will be Chavez's first start against the Red Sox after posting a 1.69 ERA in three relief appearances against them.
Oakland's Sean Doolittle, who recorded his 10th save in the opener, has not allowed a run through an AL-best 23 1-3 consecutive innings. He's given up six hits, struck out 37 and walked one during that span.