"Closers learn the hard way that the game isn't over until the last out.

For White Sox closer Sergio Santos, the lessons have been coming hard and mean in the last week.

On Friday night, he was one strike from putting the lid on the struggling Oakland Athletics, who were looking at their 11th straight defeat. The Sox were ready to celebrate a 5-3 victory that would have pulled them within 41/2 games of the division-leading Cleveland Indians and only a half-game behind the second-place Detroit Tigers.

But Santos couldn't put away Josh Willingham, who walked. And he couldn't retire the next five batters, including Scott Sizemore, whose double with the bases loaded finished Santos (2-3) and the Sox

in a crushing 7-5 loss at U.S.

Cellular Field.

''This one hurts,'' manager Ozzie Guillen admitted. ''He just lost it. I was worried about [Hideki] Matsui at the plate in that inning. [Santos] just lost it. He was trying to be too aggressive.''

The third out didn't come until Lucas Harrell retired Coco Crisp. Santos had retired the first two batters quickly, but the eternity between those outs and the last is part of what Santos is learning about in this new role."