Roger Federer was pushed to the limit in his pursuit of his first Olympic singles medal.Like so many other times on Wimbledon's Centre Court, he delivered.Federer rallied past Juan Martin del Potro of Argentina 3-6, 7-6 (5), 19-17 to reach the final. At 4 hours, 26 minutes, it was the longest three-set men's match of the Open era.Federer faces another tough challenge when he meets Britain's Andy Murray in Sunday's gold-medal match. Murray advanced with a 7-5, 7-5 victory over Novak Djokovic.Serena Williams also clinched her first Olympic singles medal, beating No. 1-seeded Victoria Azarenka 6-1, 6-2. Today, Williams will face first-time Olympian Maria Sharapova, who beat Russian teammate Maria Kirilenko 6-2, 6-3. Track and field: Poland's Tomasz Majewski became the first man since 1956 to retain an Olympic shot put title.... Ethiopia's Tirunesh Dibaba won the gold in the women's 10,000 meters while Kenyan and former Texas Tech standout Sally Kipyego took the silver.... Carmelita Jeter of the U.S. led the 100-meter heats with a time of 10.83 seconds. Women's basketball: Diana Taurasi scored 18 points and Tina Charles finished with a double-double to lead the U.S. women's team to an 88-61 win over the Czech Republic. Australia, Croatia, Canada, Turkey and France also won. Women's soccer: Abby Wambach and Sydney Leroux scored as the United States beat New Zealand 2-0 in the quarterfinals. The Americans will play Canada on Monday. France faces Japan in the other semifinal. Beach volleyball: Defending gold medalists Todd Rogers and Phil Dalhausser of the United States were knocked out of the Olympics by Italy (21-17, 21-19). Jennifer Kessy and April Ross of the U.S. beat Switzerland's Simone Kuhn and Nadine Zumkehr to advance to the quarterfinals of the women's tournament. Volleyball: Destinee Hooker scored 19 points and the U.S. women's team clinched the top spot in its pool with a preliminary-round victory over Serbia in straight sets (25-17, 25-20, 25-16). Water Polo: Maggie Steffens scored three goals and the U.S. women's team beat China 7-6 in its final preliminary-stage game. Elsewhere: Wojdan Ali Seraj Abdulrahim Shahrkhani became the first Saudi woman to compete at the Olympics when she lost her 78-kg judo fight in 82 seconds.... Moroccan runner Amine Laalou was barred from entering Britain, Morocco's sports minister said Friday. Laalou, who has reportedly failed a doping test, had been scheduled to run in the 1,500-meter heats on Friday evening.... Former TCU swimmer Alejandro Gomez finished in 23rd in the men's 1,500 freestyle.