World No. 1 Serena Williams, seeking her 17th Grand Slam title, will face off No. 5 Li Na tomorrow at the Women's Singles semifinals.

Williams, the reigning French Open champion, is 8-2 all-time against Li and has dropped only 13 games in five matches without losing a set on the New York hard courts.

In 2013 the two have already played twice, both times on hard courts in Miami and Cincinnati, and it was always Serena who exited the court as a winner, without dropping a single set.

Going back to the start of Wimbledon last year, the 31-year-old American is 96-5 with 13 trophies, including from three of the past five Grand Slam tournaments plus the London Olympics.

Li, the 2011 French Open champion, is the first Chinese player to reach the semifinals at the U.S. Open. She also reached the finals at the Australian Open where she lost to Azarenka, 6-4, 4-6, 3-6.

Li has played Williams tough, forcing a tie-breaker or 7-5 set in every defeat, including their most recent match, a 7-5, 7-5 triumph for the American in a semi-final last month at Cincinnati.

"She's a great challenge. She moves really well. She does everything well. I think the challenge of playing someone like her is how do you beat a player that does everything so well? I'm going to have to, in the next couple days, think about that and come up with an answer to that." Williams said.

"It's a tough, tough opponent," Li said. "But it's a good challenge to play against her."

"If you only think about what opponent doing, of course you already lose the match before you come to the court. For tennis you have to figure out what you have to do on the court, what you should do." she added.

Friday's TV schedule

6:00a.m. -11:00a.m., Breakfast at the U.S. Open, Tennis Channel

12:30 p.m.-6:00p.m., Women's Singles Semifinals/ Mixed Doubles Final, CBS

7:00p.m. -7:00 a.m., US Open Daily Match Encores, Tennis Channel

The U.S. Open action live stream will be available via U.S. Open Live or Watch ESPN. A full schedule may be found at the Open website.