PREVIEW-Tennis-Open-Ranking carrot adds spice to women's semis

By Simon Cambers

NEW YORK, Sept 4 (Reuters) - Women's semi-finals day will have added spice to it at the U.S. Open on Friday with the carrot of the number one ranking looming large over the four remaining protagonists.

American Serena Williams, Russians Dinara Safina and Elena Dementieva and Serbian Jelena Jankovic can all replace another Serbian, Ana Ivanovic, at the top of the rankings by winning the title in New York.

Of more immediate concern to all of them will be earning a place in the final, with Williams chasing her ninth grand slam title and the other three closing on their first.

Having defeated her sister Venus in a high-quality quarter-final, fourth seed Williams is the obvious favourite but she will have her hands full against Safina, the most in-form player on the women's tour.

The Russian sixth seed has reached the final in six of her past seven events, and was runner-up at both the French Open and Olympics.

The 26-year-old Williams, however, has been hard to derail this close to the big prize, having won 11 of her previous 13 grand slam semi-finals, and Safina admitted beating her will be a tough task.

"First of all, she is a great fighter and she's very dominant on the court," Safina, 22, said about Serena.

"She likes to put pressure on the players, so that's why it makes her a very tough opponent."