Serena Williams and Jelena Jankovic lead a four-woman assault upon the world number one ranking at the US Open, a fight that could come down to Saturday night's Grand Slam title showdown.

Dinara Safina and Elena Dementieva, each hoping to become the second Russian woman to take the top spot after Maria Sharapova's groundbreaking run in 2005, are also in the hunt to replace already ousted Serbian Ana Ivanovic at the top.

US fourth seed Williams — who dropped the Wimbledon final to sister Venus in July — and Serbian second seed Jankovic, who held the top spot for a week last month, can each take over as number one by advancing to the semifinals.

Safina, the youngest in the hunt at 22, or Dementieva would need to reach Saturday's final to unseat Ivanovic, but either could face a championship showdown for the top spot.

"Now it's so much wide open to get to this number one spot in the world," Safina said. "But we still have the Williams sisters. They're still dangerous. It's changing a little bit, so many more young players coming through."

Williams, who faces a fourth-round match Monday night with French wild card Severine Bremond, takes inspiration from 57 previous weeks atop the rankings and the praise of her newest rivals for the top spot.

"It definitely makes me want to work harder and do better," Williams said. "I believe those statements. I always believe the match is on my racquet. I think every time I lose is because of me, not because of the other person.

"That's pretty much dominance. I feel honoured that they would say that."

Eight-time Grand Slam winner Williams, however, might have to face her sister Venus in a quarterfinal for the chance to grab the top spot and that challenge has never been easy for her.

"We're both playing well," Serena Williams said. "She is always difficult. When she is at her best she is really confident. I'm not playing my best but that means I can do so much better."

If Serena faces Jankovic or Dementieva in the final, the match would decide which would take over the top ranking.

Safina — who meets German qualifier Anna-Lena Groenefeld on Monday — would need to win the crown and have Jankovic not to reach the final to be number one. A title would make Dementieve number one no matter how anyone else fares.

"It's a dream for me to become number one but I'm not thinking about that," Dementieva said. "I just want to focus on this tournament. I know if I improve my game I'm going to make it."

For Jankovic, bouncing back from an injury-hampered season and having a chance at her first Grand Slam crown are top priorities she counts upon to push her to the top.

"I've been injured and I'm finally feeling good. I don't have any problems. I don't want to ask for anything else," she said.

"I'm happy I'm getting better each time. That's the most important thing. I think I'm on the right track."

AFP