Mikhail Youzhny, the 12th seed, won the first set from unseeded Tommy Robredo, 7-5, in a fourth-round match at Louis Armstrong Stadium.
Youzhny made it to the semifinals of the 2006 U.S. Open. He was a quarterfinalist at this year's French Open.
Robredo, playing in his ninth U.S. Open, has actually made it to the fourth round of the U.S. Open six times. We'll see if he can finally advance to the quarterfinals.