US Open women's final - Williams vs. Azarenka

If there's a player out there who could possibly test No. 1-seeded Serena Williams in the U.S. Open final, it's her opponent Sunday, No. 2 Victoria Azarenka.

Williams, it's worth noting, has lost only four of 70 matches this season, and two of those defeats came against Azarenka, including just last month at a hard-court tuneup.

There's one significant switch in circumstances: Those were at smaller tournaments. This time, there's a major championship on the line, and Williams is at her best when the stakes are the biggest.
Associated Press

More U.S. Open photos:
Celebrities spotted at U.S. Open
Andy Murray's faces of defeat
U.S. Open fashion statements