Serena Williams is adding to her legendary status in what's likely the final tournament of her career.  On Wednesday, the 40-year-old took down Anett Kontaveit in three sets at the U.S. Open, punching her ticket to the third round of the singles bracket.  Kontaveit came into the match as the number two women's tennis player in the world.  Williams is now set to play doubles with her sister Venus on Thursday.  Her next solo match is Friday.