Five-time champion Roger Federer was to launch his US Open campaign on Monday, with the fortnight at Flushing Meadows his last chance to extend his streak of eight straight seasons with at least one Grand Slam title. The Swiss great, seeded third behind Serbian Novak Djokovic and defending champion Rafael Nadal of Spain, hasn't lifted a Grand Slam trophy since the 2010 Australian Open. Despite Djokovic's dominance this season, and his own recent 30th birthday, Federer remained confident he has plenty of time to add to his tally of 16 Grand Slam titles. "I'm still as professional. I'm still as hungry," said Federer, who was to take on 54th-ranked Colombian Santiago Giraldo in the night's final match on the Arthur Ashe Stadium court. "It's just a number that's changed, you know. I feel my game allows me to still play for many more years because I have a relaxing playing style. "I'm confident I can still play for many more years to come at the highest of levels." Federer has won at least one Grand Slam title from 2003-2010. He won five straight US Open titles from 2004-2008, with Argentinian Juan Martin del Potro ending his streak in the 2009 championship match. Federer lost to Djokovic in last year's semi-finals. Other marquee matches on the opening day included third-seeded Russian Maria Sharapova, the 2006 US Open champion, taking on Britain's Heather Watson. Wimbledon champion Petra Kvitova of the Czech Republic took on Romanian Alexandra Dulgheru. Kvitova, who defeated Sharapova in the final at the All England Club, was originally slated to open the action on the 22,000-seat Ashe court. Her match was moved to the smaller Louis Armstrong stadium as organizers made minor adjustments to the schedule after Tropical Storm Irene blew through New York over the weekend. Second-seeded Russian Vera Zvonareva, runner-up to Belgian Kim Clijsters here last year, faced France's Stephanie Foretz-Gacon. With three-time champion Clijsters sidelined by a stomach muscle injury, Sharapova and Serena Williams head the list of favourites in the wide-open women's field. Other women in action Monday included eighth-seeded Marion Bartoli of France and ninth-seeded Samantha Stosur of Australia and unseeded American Venus Williams. In men's action, eighth-seeded Mardy Fish makes his first Grand Slam start as the top American in the world, taking on Germany's Tobias Kamke. Seventh-seeded Gael Monfils of France faced Bulgarian Grigor Dimitrov.