Serena Williams of the United States returns a shot against Coco Vandeweghe of the United States during their first round women's singles match.

Coco Vandeweghe reacts against Serena Williams.

Serena Williams serves the ball against Coco Vandeweghe.

Agnieszka Radwanska of Poland against Nina Bratchikova of Russia.

Agnieszka Radwanska serves to Nina Bratchikova.

Andy Roddick of the US serves to compatriot Rhyne Williams.

Rhyne Williams returns a shot to Andy Roddick.

Venus Williams of the U.S. serves to compatriot Bethanie Mattek-Sands.

Novak Djokovic, of Serbia, eyes a return shot to Paolo Lorenzi of Italy.

Novak Djokovic (R) talks with Paolo Lorenzi (L) after winning their men's single first round match.

Karol Beck of Slovakia returns a shot to France's Jo-Wilfried Tsonga.

Jo-Wilifried Tsonga returns a shot to Karol Beck.

Tsonga returns another shot to Beck.

Former US Open winners' names are displayed on a wall during Day Two of the 2012 US Open.