NEW YORK: Rivals to three-time defending champion Serena Williams and Japan´s Kei Nishikori, with a Grand Slam career-best fourth seed, launched title bids Monday morning as the US Open began at Flushing Meadows.
Williams, trying to complete the first calendar-year Grand Slam since Steffi Graf in 1988, and past champions Venus Williams, Novak Djokovic and Rafael Nadal were set for later openers at Arthur Ashe Stadium.
Serbian seventh seed Ana Ivanovic, the highest-rated player in Serena Williams´ half of the draw with Sunday´s withdrawal of Maria Sharapova, played the opener at Ashe against 50th-ranked Slovakian Dominika Cibulkova.
Ivanovic and Cibulkova have split four career meetings, Ivanovic winning the most recent at Linz in 2013.
Poland´s 15th-seeded Agnieszka Radwanska, Williams´ highest-ranked potential foe in the round of 16, opened against Czech teen Katerina Siniakova.
On the men´s side, last year´s US Open finalists were set to take the court at Louis Armstrong Stadium starting with Nishikori, whose bid to become the first Asian man to win a Grand Slam crown was thwarted by Croatia´s Marin Cilic last year.
Nishikori opened against Frenchman Benoit Paire, who won his first ATP title last month in Bastad.
Nishikori, whose three titles this year included a US Open warm-up win at Washington, is 2-0 lifetime against Paire.
Ninth seed Cilic opens his title defense against Argentine qualifier Guido Pella, who has lost five of his six career Grand Slam appearances.
Serena Williams will open in the first Ashe night match against Russia´s 86th-ranked Vitalia Diatchenko while her elder sister Venus, ranked 23rd, goes against Puerto Rico´s Monica Puig.
World number one Djokovic meets Brazil´s Joao Souza while Spanish eighth seed Nadal, a possible quarter-final foe for Djokovic, faces Croatia´s Borna Coric, who won their first meeting last year at Basel.
The schedule features only two days for the men´s first round rather than three, a change from past years when organizers created a Super Saturday with the men´s semi-finals and women´s final at the cost of providing no rest day before the men´s or women´s finals.