ATLANTA — When Terry Francona decided it was best to give Jason Bay a day off on Saturday, he didn't have to worry about who would replace him in left field.

He turned to his utilityman, Mark Kotsay. And Kotsay came through again.

Kotsay's two-out RBI single in the sixth inning proved to be the game-winning run as the Sox beat the Braves, 1-0.

Atlanta starter Javier Vazquez had kept the Sox hitters off balance for much of the afternoon. Kotsay had walked and struck out before lining a single to left-center field that scored Kevin Youkilis.

"His changeup seemed to be the best pitch he was throwing against me, so I think he had it in his mind I was sitting changeup," said Kotsay. "But he threw a good fastball before a backdoor slider that I ended up driving into left field. Fortunately, I won the battle. If he won the battle it could have been a different outcome.

"We continue to grind and we have a lot of good guys in this locker room who are good baseball players, and it seems to pan out."

"Kotsay played a professional game," said Francona. "I don't know why he seems to go under the radar sometimes, but not from us. We have a guy who can play center field, left field, right field and you can move him in to play [first base]. He's a valuable guy."

jmcdonal@projo.com