
Could Serena Williams, left, and Venus Williams, right, face off at the U.S. Open? They're getting closer after Venus topped Belinda Bencic on Friday.

It was a fine win for Venus, since Bencic was seeded 12th and is one of only two players to defeat Serena Williams this year.

Marin Cilic, the men's defending champion, remained in line to repeat his 2014 heroics. It wasn't easy, though, as Cilic trailed by a set and 5-2 before winning in five sets against Mikhail Kukushkin.

Cilic stunned the tennis world when he triumphed in New York a year ago, ousting, among others, Roger Federer and Kei Nishikori.

Novak Djokovic has won two of the three majors on the men's side this year to lift his grand slam tally to nine.

Djokovic, who owns one U.S. Open title, beat Andreas Seppi in straight sets to land in the fourth round.

Benoit Paire upset Nishikori in the first round and has kept on winning. He's into the fourth round at a grand slam for the first time after breezing past Tommy Robredo.