(Flushing, NY) -- Five-time champion Roger Federer is out at the U.S. Open. The Swiss superstar suffered a straight-set loss to Spain's Tommy Robredo in the fourth round. Robredo will face second-seed and fellow countryman Rafael Nadal in the quarterfinal. Nadal needed four sets, but prevailed against Germany's Philipp Kohlschreiber. Richard Gasquet also advanced past Milos Raonic to set up a match against fourth-seeded David Ferrer, who beat Serbia's Janko Tipsarevic. On the women's side of the draw, Daniela Hantuchova, Flavia Pennetta and Roberta Vinci all moved on to the quarterfinals. Hantuchova will face the winner of Tuesday's match between second-seed Victoria Azarenka and Ana Ivanovic.