Just when Rafael Nadal ended Roger Federer's long stay atop the men's tennis rankings, Serbia's Ana Ivanovic moved back to No. 1 on the women's side.

When the WTA Tour rankings come out officially today, Ivanovic, 20, will be back on top -- a place she will hold for at least two weeks. Ivanovic, who held the No. 1 ranking for nine weeks from June 9-Aug. 11, moved past compatriot Jelena Jankovic.

Nadal, who captured the men's singles gold medal yesterday at the Beijing Olympics, will also become No. 1 today -- snapping Federer's 4 1/2-year reign atop the rankings.

Entering the Olympics, three women had a chance to be No. 1 by the end of the tournament -- Ivanovic, Jankovic and Svetlana Kuznetsova.

Jankovic and Kuznetsova could have grabbed the top spot by reaching the final in Beijing, but an opening-round loss to China's Li Na ended Kuznetsova's bid. Jankovic was eliminated by silver medalist Dinara Safina in the quarterfinals.

Ivanovic moved up despite being forced to withdraw from the Olympics due to a thumb injury. She has won two titles this year, including her first career Grand Slam championship at the French Open.

She also defeated Jankovic and Kuznetsova on the way to capturing the Pacific Life Open in Indian Wells, Calif. Ivanovic, who has compiled a 30-8 record, was runner-up to Maria Sharapova at the Australian Open in January.

Juan Martin del Potro won his fourth consecutive tournament, beating Viktor Troicki, 6-3, 6-3, to take the Legg Mason Tennis Classic championship in Washington. Del Potro, 19, ranked No. 19 in the world, has won his previous 19 matches since June 25, when he was bounced from Wimbledon in the second round.

• Second-seeded Nadia Petrova dominated unseeded Nathalie Dechy, 6-2, 6-1, to win the Western and Southern Financial Groups Women's Open in Mason, Ohio. Petrova, who reached the quarterfinals at Wimbledon this year, clinched the win with a forehand return on her second match point to win her first championship since the 2007 Tier II Paris indoor tournament and her first outdoors since the Tier I Berlin Open on clay in May 2006. Petrova, the third consecutive Russian to win the Tier III tournament, earned $28,000. France's Dechy, making her first final appearance since the 2004 New Haven event, earned $15,000.

• The Czech Republic's Lukas Dlouhy won the GHI Bronx Tennis Classic in New York, beating Argentina's Leonardo Mayer, 6-0, 6-1. In the women's final, Russia's Elena Bovina of Russia defeated Germany's Anna-Lena Groenefeld, 6-3, 7-5. Bovina overcame a 5-3 deficit in the final set.

• Pat Cash beat Jim Courier, 6-3, 6-4, to win the Hall of Fame Champions Cup title in Newport, R.I. Cash, the 1987 Wimbledon winner, earned $54,000 and his first tournament victory on the Outback Champions Series, the tennis circuit for champion tennis players 30 and over. Courier was beaten on the day he turned 38.

The Philadelphia 76ers re-signed Andre Iguodala, giving the forward a six-year contract worth a reported $80 million. Iguodala, who was a restricted free agent, helped the 76ers reach the playoffs for the first time in three years. An official announcement is expected today.

Iguodala averaged 19.9 points, 5.4 rebounds, 4.8 assists and 2.1 steals in 82 games last season. He struggled in the playoffs against Detroit, averaging 13.2 points, 4.8 rebounds, and 5.0 assists.

A Jockey Club panel will study whether the number of horses allowed into the Kentucky Derby poses a safety risk. The annual Run for the Roses at Churchill Downs in Louisville regularly draws 20 horses to the race. Typically, other races are limited to just more than a dozen. Stuart Janney, head of the Jockey Club's Thoroughbred Safety Committee, says the panel will be looking at the race's size.

The panel was created after the death of Eight Belles in the Kentucky Derby this year. The panel also has recommended a standard nationwide system for drug testing race horses.

Mike Magee and Juan Pablo Angel scored goals to lead the New York Red Bulls to a 2-0 win against Toronto FC (7-9-4) in East Rutherford, N.J. Goalie Jon Conway made four saves to record his fifth shutout of the season and the 19th of his career as the Red Bulls (7-6-7) won their second match in a row.

Jacob Dempsey had a double, home run and three RBIs as host Washington defeated the Midwest Sliders, 11-3, in the Frontier League.