Federer in walkover; Berdych advances
NEW YORK, Sept. 3 (UPI) -- Roger Federer advanced to the quarterfinals in a walkover and sixth-seeded Tomas Berdych logged a three-set victory Monday at the U.S. Open.
Top-ranked, five-time champion Federer was set to play 23rd-seeded Mardy Fish in a fourth-round match when the American withdrew, citing health concerns.
"I regret that I have to withdraw from the U.S. Open for precautionary measures," Fish said in a statement. "I was reluctant to do so, but am following medical advisement. I had a good summer and look forward to resuming my tournament schedule in the fall."
That put Federer into a men's-record 34th straight Grand Slam quarterfinal.
His next opponent with the Czech Republic's Berdych, who reached his first U.S. Open quarterfinal in 10 tries by dispatching 11th-seeded Spaniard Nicolas Almagro 7-6 (7-4), 6-4, 6-1 at Armstrong Stadium.
Berdych owns a 3-3 record in his last six matches against Federer. He upended the Swiss superstar in the 2010 Wimbledon quarterfinals.
S. Williams, Ivanovic make U.S. quarters
NEW YORK, Sept. 3 (UPI) -- Former world No. 1s Serena Williams and Ana Ivanovic will meet in the quarterfinals of the U.S. Open after each won fourth-round matches Monday.
Three-time champ Williams only needed 56 minutes to decimate the Czech Republic's Andrea Hlavackova, 6-0, 6-0, as the Olympic gold medalist eased into the next round at Arthur Ashe Stadium.
Her opponent will be Ivanovic, who advanced with a 6-0, 6-4 decision over Bulgarian Tsvetana Pironkova at the USTA Billie Jean King National Tennis Center.
The 12th-seeded Serbian, making her first appearance in a major quarterfinal since the 2008 French Open, is 0-3 lifetime against Williams.
Bears sign defensive tackle Okoye
CHICAGO, Sept. 3 (UPI) -- Defensive tackle Amobi Okoye has signed a one-year contract with the Chicago Bears, the team said Monday.
Okoye, a five-year veteran, started only one game but played in all 16 contests for the Bears last season, racking up four sacks and 27 tackles.
The former first-round draft selection of the Houston Texans signed with Tampa Bay in the off-season, but was released Friday after missing time while recovering from arthroscopic knee surgery.
Okoye, 25, has compiled 15 sacks and 165 tackles in his 78-game career.
The Bears released defensive tackle Brian Price to make room for Okoye on the roster.
Nadal out with torn left knee tendon
MADRID, Sept. 3 (UPI) -- Spanish tennis star Rafael Nadal said Monday he has a partially torn patella tendon in his left knee and will be out of action for at least two months.
Nadal. who is sitting out the current U.S. Open and missed the Olympics tennis tournament last month, said he will also be sidelined for Spain's Davis Cup semifinal next week.
"I have to recover and I'll be back once the pain is gone," Nadal said.
The 11-time Grand Slam winner's last match came in the second round at Wimbledon in June, when he fell to the Czech Republic's Lukas Rosol.
