Kendrick drove in Albert Pujols with a sacrifice fly in the 10th inning, and Los Angeles opened a two-game lead atop the major league standings with a 4-3 victory Thursday night over Oakland, which finished the game under protest over a ninth-inning obstruction call.
Josh Hamilton had a 10th-inning single as the Angels (80-53) edged Oakland (78-55) to begin a four-game series between the California clubs with the majors' two best records.
They've already got a rivalry, and Kendrick knows the postseason stakes make it even more exciting.
"Every time we play these guys, it's a great game," said Kendrick, who also had two hits. "We've already had a few walk-offs against these guys. We know we've got to play them ... down the stretch."
Pujols drew a leadoff walk from Ryan Cook (1-2) in the 10th, and Hamilton moved him to third with a bouncing hit up the middle.
Kendrick's long fly to right easily drove in the slow-footed Pujols, setting off a playoff-worthy celebration by the Angels, who have won 12 of 16.
"There's been a lot of times I've failed in that situation, so you just try to take from those experiences," Kendrick said.
Fernando Salas (5-0) pitched a perfect 10th for the Angels. He has retired 38 of his last 41 batters.
Oakland protested the game after Erick Aybar hit a short chopper up the first-base line to open the ninth. He ran into Dan Otero as the pitcher fielded it and bumped into first baseman Brandon Moss.
Home plate umpire Greg Gibson immediately awarded first base to Aybar, prompting a lengthy argument from A's manager Bob Melvin. The Angels then loaded the bases with one out, but Kole Calhoun popped up and Mike Trout grounded to third against Cook.
Melvin thinks Aybar went out of the baseline and tried to hit the fielder.
"I thought they would overturn it, based on what we were seeing," the manager said. "It was pretty evident."
Moss, according to the San Francisco Chronicle, said the protest should be upheld because the only person he ran into was Otero, neither of them were in the baseline and Aybar "ran out of it," referring to the baseline, to veer into Otero.
"Obviously, I'm confused by it," Moss told the Chronicle. "Dan actually ran into me, not Aybar. Then when Dan caught the ball, Aybar veered in, I know he veered inside the line. There is video to prove it."
Angels manager Mike Scioscia disagreed, saying Aybar "had nowhere to go."
"I was running, and both guys just got in my way," he said after the game, according to MLB.com. "I was trying to, but I couldn't go anywhere. I'm running and when I pick my head up, I see the pitcher and first baseman together. I want to move, and they're on top of me. I kept running."
Crew chief Gerry Davis said the obstruction ruling --which was clarified after the game to an obstruction on Moss -- was a judgment call by Gibson. Judgment calls can't be protested, according to Rule 4.19.
Sonny Gray pitched seven innings of six-hit ball for Oakland, but left without a decision for the first time in 11 starts.
C.J. Wilson yielded seven hits and blew a three-run lead while pitching into the sixth inning for the Angels.
Gordon Beckham had an early two-run single for the Angels, but Oakland closed to 3-2 in the fifth. Josh Donaldson led off the sixth with his 26th homer, but Angels reliever Mike Morin struck out pinch-hitter Stephen Vogt with the bases loaded to preserve the tie.
The A's took two of three from the Angels at the Coliseum last week. The clubs also begin the final week of the regular season with a three-game series in Oakland.
"I think that's our fourth extra-inning game here," Otero said. "They're a great ballclub, and we know we are, too, so it's a battle every time out. They're going to battle us to the end, and we know we're going to give it all we've got."
Athletics: SS Jed Lowrie took live batting practice for the first time since breaking his right index finger.
Angels: Reliever Joe Thatcher's sprained left ankle still isn't ready for a rehab assignment.
Athletics: Jon Lester (13-8, 2.53 ERA) held the Angels to five hits and a run over seven innings in a no-decision last weekend.
Angels: Jered Weaver (14-7, 3.72 ERA) looks to secure the fourth 15-win season of his career.
The Associated Press contributed to this report.
Angels Walk Off Against A's
Howie Kendrick's sacrifice fly in the bottom of the 10th lifted the Angels past the A's 4-3.