Serena Does Letterman

by Ben Rothenberg on Jul 8, 2009 2:45 AM EDT

The woman with 11 slams made an appearance at 11:30 last night on The Late Show With David Letterman, a traditional stop on victory laps for American slam winners.Letterman asked Serena about grunting, her knee injury from a couple years back, and, out of nowhere, drinking. And she was pretty...