Rafael Nadal [ Images ] and Ana Ivanovic [ Images ], both ranked world number one, were named on Tuesday as the top seeds for the US Open [ Images ] which begins at Flushing Meadows on Monday.

It is the first time that Spaniard Nadal, who replaced Roger Federer [ Images ] at the top of the men's rankings on Monday, has been the top seed at a Grand Slam tournament.

• Perfectionist Nadal still not satisfied

Federer, who has won the US Open in each of the past four years, is seeded second, the first time he has not been the top seed in a Grand Slam since the Australian Open [ Images ] of 2004.

Novak Djokovic [ Images ], the Australian Open champion and runner-up to Federer last year in New York, is seeded third, with Spaniard David Ferrer fourth.

French Open [ Images ] champion Ivanovic, chasing her first US Open title, heads the women's list for the first time, with fellow Serbian Jelena Jankovic [ Images ] at number two.

• History repeats itself

Former champion Svetlana Kuznetsova [ Images ] of Russia [ Images ] is seeded three, ahead of American Serena Williams [ Images ].

Olympic champion Elena Dementieva [ Images ] is seeded fifth, with French Open and Olympic Games [ Images ] runner-up Dinara Safina [ Images ] sixth and Wimbledon [ Images ] champion Venus Williams [ Images ] at seven.

The draws for the final Grand Slam event of the year will be made on Thursday.