On a day where some of the top seeds in both the men's and women's singles draws are in action, all eyes will once again be on Andy Roddick. The U.S. tennis legend and 2003 U.S. Open champion, who announced last week that he would retire after this tournament, faces Fabio Fognini at 1:30 ET Sunday. Roddick rolled through his first match since announcing his retirement, a straight-sets win over Bernard Tomic. Fognini was equally quick in knocking out Guillermo Garcia-Lopez in the third round.

Elsewhere in the men's bracket, second-seeded Novak Djokovic faces No. 31 Julien Benneteau at 11:00 a.m. ET. Ninth-rated John Isner, the highest-ranked American man in the draw, takes on No. 19 Philipp Kohlschreiber in Sunday's late match, scheduled for approximately 9 p.m. ET. No. 4 seed David Ferrer plays Lleyton Hewitt at 11 a.m. ET. No. 7 Juan Martin del Potro, No. 8 Janko Tipsarevic, and No. 13 Richard Gasquet are also in action.

On the women's side of the draw, third-seeded Maria Sharapova takes the stage in Sunday night's primetime match, facing No. 19 Nadia Petrova. The 2006 U.S. Open champion has had little trouble advancing through the first three rounds, dropping just seven games. Sharapova has not advanced past the fourth round since her 2006 win, however. The match is scheduled to begin at 7 p.m. ET.

In other women's action, top seed Victoria Azarenka faces Anna Tatishvili at 3:30 p.m. Fan favorite Laura Robson is back in action against No. 7 Samantha Stosur in the late afternoon match at Louis Armstrong Stadium Court; the match is scheduled for approximately 3 p.m. ET. No. 5 Petra Kvitova takes on No. 11 Marion Bartoli at approximately the same time.

The full schedule and draw are available at the U.S. Open official website. Television coverage begins on CBS at noon ET.

For ongoing match updates and top notch analysis of the 2012 U.S. Open, make sure that you check out SB Nation's dedicated tennis hub.