Bay not deep thinker

Bay had reason to think about anything but becoming a hero. He has learned the worst thing he can do for his swing is try to hit a home run. Against Mariano Rivera, Bay had gone 0 for 4 with two strikeouts. A home run "was the last thing on my mind," Bay said.

But then he unleashed his simple, sudden swing, his hips flying open and his wrists rolling. Rivera had left a cutter over the plate, and Bay drove the ball to the deepest part of Fenway Park. He watched it eke over the part of the Green Monster that creeps into center field, the blast that tied the score in the bottom of the ninth, made the Red Sox think Rivera is a little less invincible, and eventually led to a 5-4, 11-inning victory.

Bay sent the game into extra innings, the obvious highlight of his 3-for-5 night. He also made a diving catch in the eighth inning with the bases loaded that preserved the Red Sox' chance to win and his chance to become one of the primary figures.

He came to the plate in the ninth with two outs and Kevin Youkilis on second base. His history against Rivera was far from his mind, but the experience helped. "Once you've seen a guy, you kind of get an idea what he's going to do," Bay said. Between the eighth and ninth, he had chatted with a teammate about Rivera's singular ability to dominate with one weapon.

"His cutter is his pitch," Bay said. "If he puts it in the spots he wants every single time, there's nothing you're going to be able to do."

Rivera started him with a ball. The next pitch, he fired a cutter that didn't bite like a Mariano Rivera cutter bites, and Bay knew it had caught more of the plate than Rivera wanted. He swung. The ball sailed into center, high into the black sky. Youkilis stood on second base. "Once he hit it," Youkilis said, "it sounded so loud."

In the dugout, Dustin Pedroia noticed the flag above center field flapping and thought the ball had a chance to leave the park. Bay wasn't so sure. He thought he had hit the ball well, and he knew Rivera's heavy cutter provides power for the hitter. But Bay doubted his own power. He had hit a ball to right field earlier that he thought might fly into the bullpen, but it didn't even reach the warning track.

And this ball was headed to the worst place to try for a home run. "That is the hardest place in this ballpark to hit it," Youkilis said. "You know, lefthanders all say 380 [feet] to right field. But that left-center field is so high. If you hit one out there, you get all of it."

Bay knew that; in his limited time playing at Fenway, he had never done it. He thought, "Get up," as he raced around first. He watched the ball fall to the top of the wall, on top of the yellow line that separates it from the bleachers. He saw third base umpire Brian O'Nora dash into center and signal home run immediately.

Bay circled the bases and walked back to the dugout. Pedroia thumped him on the back. Bay's strength as a player derives from his even-keeled nature, that he is never overwhelmed by a moment. His attitude proved pivotal last night. Bay created the newest Yankees-Red Sox memory without even trying.

"The more I try to hit home runs, the more detrimental it gets to my swing," he said. "Ultimately, I got some barrel on it. But it was definitely not something I was trying to do."

Adam Kilgore can be reached at akilgore@globe.com