World Number One Serena Williams today made a shocking exit from the Australian Open Tennis tournament, the first Grand Slam of the season, at Melbourne. In the Women's Singles pre-quarterfinals, Serbia's Ana Ivanovic defeated injury-hit Serena, 4-6, 6-3, 6-3, denying the American an 18th major title and the chance to win a rare calendar-year Grand Slam. Na Li of China and Italian Flavia Pennetta also booked the last-eight berths.