"Left fielder Josh Willingham was busy demolishing a Gatorade bar, so he didn't witness the biggest moment of the A's season as it began unfolding Monday.

No matter.

His ears told him all there was to know about Hideki Matsui's walkoff homer that beat the Texas Rangers 5-4.

"I took a bite of my bar and heard the crack," Willingham said. "I looked up and saw the ball and knew it was a home run."

Matsui ended things quickly in the bottom of the 10th, crushing the first pitch from lefty Darren Oliver deep over the right field wall.

It marked Matsui's biggest highlight yet in an A's uniform, and it put an exclamation point on a morale-boosting four days for his club, which moved within one game of first place in the American League West.

The A's took three of four from Texas, the defending A.L. champion, and they did it Monday with a weapon the Rangers themselves are better known for -- the long ball.

The A's connected for three homers -- one from Kurt Suzuki, a game-tying blast from Willingham in the eighth and Matsui's no-doubter in the 10th, the team's first walkoff homer of 2011.

Matsui was mobbed by jubilant teammates as he crossed home plate.

"Definitely the most exciting game of the year," A's manager Bob Geren said. "I've never seen this group this animated after a win. I hope they didn't hit their head on the dugout. That ball came off the bat and it was loud.""