The Angels have lost five straight, and the A's moved a season-high two games ahead of Los Angeles in the AL West.
"Obviously, he's one of the best pitchers in the game," Kielty said. "He got to 2-0. I wanted to see a fastball, and I was going to go hack no matter what.
"Sometimes that's a case where you might take a pitch and see if he goes 3-0, but in that situation against a guy like that, you want to try to get a fastball. He threw a good pitch to hit and I was able to capitalize on it."
Zito gave up only three hits, walked two and struck out nine in nine innings, with one of the hits Robb Quinlan's solo homer in the eighth.
Colon allowed six hits, walked one and struck out three in his 9 1/3 inning stint, the Angels' longest since Mark Langston went 10 innings in a 3-2, 11-inning loss to the Chicago White Sox on Sept. 27, 1992.
Oakland's only run off Colon came on Dan Johnson's RBI single in the fourth.
"I probably would have paid to go see that one," Oakland manager Ken Macha said. "You've got a premier matchup with two of the best pitchers in the league right now."
Zito figured it would be a good matchup.
"You know going up against a Cy Young candidate that it's going to be a close one, so you've just got to go out and attack the hitters and hopefully come out on top," said Zito, the 2002 AL Cy Young Award winner.
He expects more of the same in the remaining games against the Angels.
"It's probably going to be pitchers' duels from here on out -- in this series, and then we've got them at home for four," he said, referring to the series at Oakland from Sept. 26-29.
Kiko Calero (4-1) pitched the 10th inning to get the win, then Huston Street pitched the 11th for his 18th save in 22 chances. With runners on second and first, Street got Vladimir Guerrero on a game-ending grounder to second.
Los Angeles manager Mike Scioscia was frustrated that the Angels wasted Colon's fine outing.
"I don't think there's any way to sugarcoat it, our offense has been soft," Scioscia said. "Bartolo couldn't have pitched any better.
"Zito has pitched a lot of good games, but I know if I've ever seen him pitch a better game. Everything was working for him. Bart matched him pitch for pitch, but we couldn't come up with any offense."
Oakland won in extra innings for the second time in as many days, and is 10-3 overall.
- Los Angeles 3B Dallas McPherson had arthroscopic surgery to remove a bone spur and clean out the joint in his left hip. McPherson is expected to be on crutches for up to 10 weeks before beginning rehab.
- Oakland SS Bobby Crosby sat out his third straight game because of a bruised left ankle.
- A's CF Mark Kotsay missed his second game with back soreness and will return to Oakland to be examined.
- The Angels acquired LHP Jason Christiansen from San Francisco for two minor leaguers, LHP Dusty Bergman and RHP Ronnie Ray. After the game, the Angels optioned RHP Joel Peralta to Triple-A Salt Lake to make room for Christiansen.