Aug. 29 (Bloomberg) -- Venus Williams advanced at the U.S. Open against an opponent whose arrival at the season's final Grand Slam tournament was delayed until a few hours before the first-round match by visa and weather problems.

Roger Federer also won his opening match tonight, defeating Colombia's Santiago Giraldo 6-4, 6-3, 6-2. It was the first Grand Slam match for Switzerland's Federer since he turned 30 earlier this month.

Federer, who won five straight U.S. Open titles from 2004-08 and holds the men's record with 16 Grand Slam singles championships, has won at least one major event every year since 2003, though none so far in 2011.

Williams, 31, who took the championship in 2000 and 2001, won 6-4, 6-3 against Russia's Vesna Dolonts, who said in a televised pre-match interview that she only received a visa three days ago and then had a flight into New York canceled by Hurricane Irene.

Williams, ranked 36th on the WTA Tour, is unseeded at the tournament for the first time since 1997 and hadn't played since losing in the fourth round at Wimbledon. She was sidelined for several weeks by illness.

"I just want to play tennis," Williams said in a news conference. "It doesn't matter what the tournament is. Obviously the Open is huge, but I just want to play."

Kvitova Out

Former champion Maria Sharapova needed three sets to advance to the second round, while Wimbledon champion Petra Kvitova was upset by unseeded Romanian Alexandra Dulgheru.

Mardy Fish, at No. 8 the top-seeded American man, won in straight sets as the tournament began without delays at the National Tennis Center one day after wind and rain lashed the New York area.

Sharapova, the No. 3 seed from Russia who won in 2006, beat Heather Watson, a 19-year-old Briton, 3-6, 7-5, 6-3 in a 2-hour, 34-minute match in Arthur Ashe Stadium.

"The goal sometimes on days like this is just to get through it," Sharapova, who is 12-0 in three-set matches this year, said in a televised interview. "I hung in there. She played great and all I can do is improve for the next one."

Dulgheru, ranked 48th on the WTA Tour, beat fifth-seeded Kvitova of the Czech Republic 7-6 (7-3), 6-3 on the Louis Armstrong Stadium court. Kvitova, who in July beat Sharapova in straight sets to claim her first Grand Slam title, made 52 unforced errors in the loss, compared with 23 for Dulgheru.

Fish Wins

Fish beat Germany's Tobias Kamke 6-2, 6-2, 6-1 in the opening match on the Ashe Stadium court, hitting 28 winners compared with 10 for Kamke.

"It's probably pretty easy to say this is one of the biggest tournaments I've ever played," Fish, who next will face qualifier Malek Jaziri of Tunisia, said at a news conference. "I've never come into a Grand Slam ranked higher."

Play began today following minimal damage at the site from Irene, which had weakened from a Category 3 hurricane to a tropical storm by the time it reached New York City yesterday morning. Attendance for the opening day session of the tournament was 32,909, as compared with 36,082 last year.

Croatia's Marin Cilic topped American wild card Ryan Harrison 6-2, 7-5, 7-6 (8-6) on the Armstrong court. Cilic broke Harrison's serve seven times during the match.

Harrison, 66th in the ATP World Tour rankings and one of 14 U.S. men entered in the tournament, last year upset 15th-seeded Ivan Ljubicic of Croatia in the first round as a U.S. Open qualifier.

"It's obviously pretty disappointing to be out of here, you know, when half the people haven't even arrived yet with the hurricane," Harrison said at a news conference.

Seeds Advance

Also in the men's draw, seeds Tomas Berdych and Radek Stepanek of the Czech Republic, Richard Gasquet and Michael Llodra of France, Janko Tipsarevic of Serbia, Alexandr Dolgopolov of Ukraine and Marcel Granollers of Spain advanced. No. 15 Viktor Troicki of Serbia lost in five sets to Alejandro Falla of Colombia.

Women's second seed Vera Zvonareva of Russia reached the second round. So, too, did seeds Marion Bartoli of France, Samantha Stosur of Australia, Peng Shuai of China, Dominika Cibulkova of Slovakia, Julia Goerges of Germany and Lucie Safarova of the Czech Republic.

No. 12 seed Agnieszka Radwanska of Poland defeated younger sister Urszula 6-2, 6-3. It was the 19th time sisters have met in a Grand Slam match since the Open era began in 1968, and the first time since 1993 that sisters other than Venus and Serena Williams have met in a major tournament. Katerina Maleeva defeated sister Magdalena in the 1993 U.S. Open.

In a battle of U.S. wild cards, Madison Keys beat Jill Craybas 6-2, 6-4.

--Editors: Dex McLuskey, Dan Baynes