By Nicole Rojas (staff@latinospost.com) | First Posted: Aug 31, 2012 11:26 AM EDT

Thursday was an exciting day at the U.S. Open with several key players advancing to the third round and a retirement announcement from U.S. player and former No. 1-ranked Andy Roddick.

No. 4-ranked Serena Williams breezed through her second round against Maria Jose Martinez Sanchez, beating the Spaniard in two sets, 6-2 and 6-4. Sister Venus Williams was not so lucky during her match and was defeated by No. 6-ranked Angelique Kerber. Kerber, who beat Williams in three sets 6-2, 5-7, and 7-5, made it to the semi-finals at last year's U.S. Open, according to Bleacher Report.

Thursday also saw another victory for No. 2-ranked Agnieszka Radwanska from Poland when she defeated Spaniard Carla Suarez Navarro in three sets, 4-6, 6-3, and 6-0. According to Fox News, Radwanska will play against Serbian Jelena Jankovic, the former No. 1-ranked player.

No. 1-ranked Roger Federer didn't disappoint, defeating German Bjorn Phau in three easy sets, 6-2, 6-3, and 6-2. Phau, who beat Federer when they first met in 1999, said "The way he played today, he was really focused, really playing well, actually," the Washington Post reported.

Off the courts, No. 20-ranked American player Andy Roddick announced that he will be retiring after the U.S. Open ends in September. Roddick, who is scheduled to play Friday night against Bernard Tomic, said, "All right, well thank you all for coming. I'll make this short and sweet: I've decided that this is going to be my last tournament. I just feel like it's time."

The former No. 1 seeded player also added that he did not feel "healthy enough or committed enough" to continue for another year. Serena Williams, a close friend of Roddick and fellow tour member, told The Telegraph, "He has a great attitude and a lot of people look up to him. It's incredibly sad for me to lose a friend on tour. It's going to be hard."

Despite the announcement, Roddick is still in the running to win the title this year.

Players to look out for Friday morning include No. 2-ranked Novak Djokovic, who is playing against Rogerio Dutra Silva, No. 3-ranked Maria Sharapova, who is playing against Mallory Burdette, and No. 4 ranked David Ferrer, who is playing against Igor Sijsling.

The Williams sisters will be playing a doubles match against Klaudia Jans-Ignacik and Kristina Mladenovic Friday night at the Louis Armstrong Stadium.

Video Highlights

Video highlights of the open can be found here.

Roddick Announces Retirement (VIDEO):

Friday Schedule:

Men's Singles- Rogeria Dutra Silva vs. Novak Djokovic at Arthur Ashe Stadium (11 a.m. EST)

Women's Singles- Maria Sharapova vs. Mallory Burdette at Arthur Ashe Stadium (11 a.m. EST)

Men's Singles- Igor Sijsling vs. David Ferrer at Grandstand (11 a.m. EST)

Men's Singles- Andy Roddick vs. Bernard Tomic at Arthur Ashe Stadium (7 p.m. EST)

Women's Singles- Victoria Azarenka vs. Jie Zheng at Arthur Ashe Stadium (7 p.m. EST)

Women's Doubles- Klaudia Jans-Ignacik and Kristina Mladenovic vs. Serena Williams and Venus Williams at Louis Armstrong Stadium (11 a.m. EST)

FULL FRIDAY SCHEDULE

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