"It's huge. We definitely capitalized on their team being beat up," Zito said.
Jorge Posada homered and Robinson Cano had three hits for the Yankees, who held a team meeting before the game. They matched a season high with their fourth straight loss -- all at home -- after winning 11 of 14 overall.
"I don't think you can just go to that and say that's the reason we've been scuffling," Derek Jeter said. "They're not here and they're not going to be here for a while. That's an easy excuse."
Zito (7-3) beat New York for the first time since May 2003 despite tying a career high with seven walks. The 2002 AL Cy Young Award winner allowed five runs and four hits in seven innings before a sellout crowd of 54,570.
Huston Street worked a perfect ninth again for his 14th save in 17 chances. He earned his fourth save in four days for the first time in his career and closed out all three games in the series -- Oakland's first sweep at Yankee Stadium since July 1994.
"A one-run game and facing the same three guys I faced yesterday I think got the adrenaline going," Street said. "You look forward to these situations as a closer."
Shawn Chacon came off the disabled list and lasted five-plus innings for the Yankees in his first outing since May 16. He gave up five runs -- three earned -- and six hits.
"It wasn't a bad pitch, but it wasn't a good one. I beat him with the pitch, he just got the fat part of the bat on it," Farnsworth said. "I guess the wind just kept on pushing it further and further into the corner."
That gave Johnson his first career multihomer game and made Zito a winner for the fourth consecutive start. The lefty improved to 3-9 lifetime against the Yankees, including 1-2 this season. He entered 0-7 against New York since his previous win on May 4, 2003.
Zito walked the bases loaded in the first before Bernie Williams delivered a sacrifice fly and Cano hit a two-out RBI single.
Johnson had a solo shot in the second, and Swisher's 17th homer tied it in the third.
With two outs, Swisher hit a long drive to left-center between Johnny Damon and Cabrera. Damon appeared to have the ball lined up as they closed in on each other, but the rookie's glove hit Damon in the face and they collided on the warning track.
"I was trying to run to a spot and we got there at the same time," Damon said. "It was unfortunate."
The ball rolled about 15-20 feet away as Swisher circled the bases. He beat the relay throw with a slide at the plate for the first inside-the-park homer at Yankee Stadium since A's teammate Eric Chavez hit one on Aug. 8, 2000.
"When I hit the bag at third, it felt like somebody dumped a fridge on my back," Swisher said.
The next time up, Swisher was robbed of extra bases -- perhaps a homer -- when Damon made a leaping catch at the fence.
Jay Payton's double set up Oakland's two-run fourth. One run scored on a passed ball, the other on Kendall's sacrifice fly.
Jeter snapped an 0-for-14 skid with an RBI double in the fifth, and Posada's two-run homer with two outs gave New York a 5-4 lead.
A leadoff walk and a throwing error by third baseman Alex Rodriguez helped the A's tie it in the sixth on Kendall's RBI groundout. The Yankees had a chance for an inning-ending double play, but reliever Scott Proctor struggled to pull Kendall's comebacker out of his glove and could only get a force at second.
"We finally put together a decent game, we just didn't close the deal," Damon said. "We'll overcome this."
- The last time Oakland swept a three-game series from the Yankees was at home in August 2001.
- Swisher hit the 22nd inside-the-park shot in Oakland history. Bobby Crosby hit the previous one on July 5, 2005, at Toronto.
- The A's won the season series, 6-3, for the first time since 2003.
- Zito is 1-1 with a 1.32 ERA in two postseason starts against the Yankees.
- Jeter (bruised right thumb) started his third straight game as the designated hitter. He hopes to return to shortstop Tuesday night against Cleveland.
- Giambi was hit by a pitch Saturday. X-rays were negative, and the Yankees hope he'll be able to play Tuesday.
- The A's went 5-1 on their road trip to Cleveland and New York.