New York: All the ingredients are in place for a classic finish to the US Open women's singles tournament with a stellar cast set to take the court on Friday in semifinal action at the year's final Grand Slam.
The four survivors include the winners of this year's three slams: Victoria Azarenka (Australian Open), Maria Sharapova (French Open) and Serena Williams (Wimbledon) as well as Roland Garros runner-up Sara Errani, who looms as the underdog after drawing Williams in the semis.
As the greatest player of her generation with 14 Grand Slam titles, Williams is the overwhelming favourite to beat Errani and is in great form, having won her fifth Wimbledon title in July then her first Olympic singles title.
She has already won the US Open three times, but only once since claiming her second title in 2002. Last year, she suffered a shock loss to Australia's Sam Stosur, but believes she is reaching her peak at the right time this week.
After a slow start, Williams has been steadily getting better with each match and is the only woman left yet to drop a set in the tournament.
"I feel like I'm going to get more focused and serious and start playing Serena tennis in the next couple of rounds," she said. "I didn't think I came into this tournament playing my best, but I definitely played better in the last two matches. I hope I have two matches left, and I can give it 200 percent."
Williams won her three previous clashes with Errani but the pair have not played each other since 2009, long before the Italian began her rapid move up the rankings.
"She's playing well. She made the final at Roland Garros and now semis here, potential finals," Williams said. "I can't underestimate her. It's not by luck she's been doing so well."
The 25-year-old Errani is having the best season of her career. She has won four titles and made her first Grand Slam singles final at the French Open and climbed 35 places to be ranked 10th in the world.
She also won the doubles title in Paris and is through to the doubles final in New York, ensuring she will take over the world number one spot when the doubles rankings are released on Monday, but knows the enormity of the challenge she faces.
"Serena is playing unbelievable," Errani said. "I just have to go on the court and try to play my game the best I can."
While Williams is at short-odds to win her semi, there is no clear favourite between Azarenka and Sharapova. The pair have played each other nine times with Azarenka holding a 5-4 lead.
Azarenka beat the Russian in the final of this year's Australian Open to claim her maiden Grand Slam title and capture the number one ranking but Sharapova has already won a US Open, in 2006, and won the French Open in June to become just the 10th woman to win all four Grand Slam titles.
"She beat me in Australia quite easily and I would love to get my revenge at a Grand Slam," Sharapova said.
Azarenka is appearing in her first semifinal at Flushing Meadows and almost did not make it after she was pushed to a third set tiebreaker in her quarterfinal with Stosur.
But she survived and the 23-year-old now has her sights set on beating Sharapova to make the final.
"Being in the semifinals of the US Open for the first time is an incredible feeling for me but I definitely I don't want to stop," she said. "I'm going to do absolutely everything I have."