"We're on a nice roll right now," said manager Bob Melvin, whose team has won eight straight at the Oakland Coliseum. "The more games you win, the more confidence you have. It seems to be playing out right now."
Oakland won all seven games against Detroit this season and has a franchise-record 12 consecutive victories over the Tigers.
The A's blanked the Tigers on Friday night and allowed only an unearned run Saturday. It's the first time in Oakland history that the team did not give up an earned run in a series of three or more games.
"We know the bullpen's the strength," Cahill said. "We know the guys can score, so it helps us out and gives us confidence to go out there and trust our stuff in the zone, knowing that we have the offense that can pick us up."
Cahill (4-2) was masterful in one of his most dominant outings this season. The right-hander walked one and yielded three hits while pitching through traffic much of the afternoon.
Cahill retired Jim Aducci on a swinging strikeout with the bases loaded to end the first, got James McCann to line out with a runner at second in the fourth and then struck out Jeimer Candelario looking to end the sixth.
It's the first time Cahill has won three consecutive starts since 2012. He improved to 3-0 with a 0.99 ERA in seven starts at the Coliseum this season.
"It's always easier when you're used to pitching in a place, as far as the backdrop," Cahill said. "You're used to the mound. It's just what you're most comfortable with."
Davis provided all the offense Cahill needed with his 31st home run leading off the fourth against Tigers starter Francisco Liriano (3-6). It was his 10th in 16 games since the All-Star break.
"When he first hit it I'm thinking base hit to center field," Melvin said. "Then you watch it carry. Next thing you know it's over the fence. He definitely does not have to square it up to hit a home run."
Chapman hit his 15th homer, a two-run shot off Daniel Stumpf, in the seventh.
Olson homered in the eighth, his 22nd.
Mike Gerber had two hits for Detroit.
"That team can be very explosive and they made us pay a couple of times," Tigers manager Ron Gardenhire said. "Kind of like how the whole series went."
Oakland acquired right-hander Shawn Kelley for international slot money from the Nationals, who no longer wanted the reliever after he slammed his glove to the ground and glared into Washington's dugout during a game last week. The Nationals also sent cash to the A's in the swap.
Laureano had a busy three days after being called up from the minors. He delivered the game-winning single in the 13th inning Friday for his first major league hit, made a pair of defensive gems Saturday and then drove in Olson with the second of his three hits Sunday.
"Today I just relaxed and felt good," Laureano said. "I felt like I usually play."
Athletics: Chad Pinder (car accident) is expected to return Tuesday when Oakland begins a three-game series against the Dodgers. Pinder hit off a machine in the batting cage and has already been doing fielding work.
Tigers: LHP Matthew Boyd (6-9, 4.22 ERA) faces the Angels for the second time this season Monday in Anaheim. Boyd pitched five scoreless innings to beat Los Angeles on May 28.
Athletics: LHP Sean Manaea (10-7, 3.38) will make his seventh interleague start Tuesday against the Dodgers, tying him for second-most in major league history for one season.
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