It's anything but business as usual at the U.S. Open now that former No. 1 Kim Clijsters is back on the scene. The Associated Press reports that Clijsters temporarily retired from tennis after winning the 2005 championship in order to have a baby. Now she's back, and 18-month-old Jada roots for her mom up in the players' lounge. It seems to be working. Clijsters upended the tournament's rankings by beating No. 3 Venus Williams on Sunday, 6-0, 0-6, 6-4, circumventing the Williams-Williams semifinal match that seemed all but carved in stone. That's not the only upset on the women's side of things. Dinara Safina, the top-seated player, is out of the running after a third-round loss; Maria Sharapova is also gone, thanks to 17-year-old Melanie Oudin; Jelena Jankovic, seeded fifth, lost earlier in the week; and Vera Zvonareva, ranked seventh, lost by six points on Sunday.