Today's field is much deeper than it was in 2003, though.
From 2002 to 2003, notable people Clijsters defeated include Conchita Martinez (altho at latter stage of her career), Serena Williams, Venus Williams, Justine Henin, Jennifer Capriati, Daniela Hantuchova, Jelena Dokic, Ai Sugiyama, Amelie Mauresmo, and Elena Dementieva. Also took Martina Hingis and Monica Seles to 3 sets in 2002 (even though it was at the very latter stages of their career but they still held their own).
From 2010 to 2011, notable people Wozniacki defeated include Vera Zvonareva, Francesca Schiavone, Elena Dementieva, Marion Bartoli, Victoria Azarenka, Shahar Peer
, slumping Sharapova, slumping Jankovic, slumping Kuznetsova, and slumping Ivanovic. Also took Justine Henin and Li Na to 3 sets in 2010/2011.
fyi not a post bashing Wozniacki but get your perspectives right.