Top seed Caroline Wozniacki made comfortable progress into the second round of the US Open with a 6-1 6-1 victory over American wild card entrant Chelsey Gullickson.
The 20-year-old Wozniacki, seeded first here due to the absence of Serena Williams with a foot injury, arrived at Flushing Meadows in excellent form having won in Montreal and New Haven in the space of six days last week.
Wozniacki saved a break point in game one and it proved to be the first of six points she won in a row en route to breaking Gullickson instead, setting the tone for the first set which began just before midnight in New York.
A long forehand from the American gave Wozniacki a second break in the sixth game and allowed the Dane to serve for the first set, and she wrapped up the first set with the match only 30 minutes old. Gullickson was gutsy but too many unforced errors ultimately cost her dearly as the second set followed the pattern of the first.
Wozniacki will be aiming to go one better here than she did last year, when she lost to Kim Clijsters in the final.
Much earlier in the day, fourth seed Jelena Jankovic admitted she had enjoyed a lucky escape after scraping past Simona Halep, winning 6-4 4-6 7-5 but only after world number 96 Halep had served for the match at 5-4 in the decider.
"First-round matches are never easy and today was really hard. It wasn't my best game, so I had to work hard to get through," Jankovic said. "It was tough, I was lucky to get through and to have another chance."
Jankovic will face Croatia's Mirjana Lucic in the second round, the 1999 Wimbledon semi-finalist who vanished off the tour for several years due to personal and financial problems.
Lucic, who beat Australian Alicia Molik 7-6 6-1, turned professional in April 1997 at the age of 15 and promptly won her first tournament, and was still just 15 when she won the Australian Open doubles title in 1998 with Martina Hingis.
"I don't want to go into the reasons about everything, it was just unfortunate why I haven't played," Lucic said. "It wasn't because I was sick of tennis or anything like that. It was just a lot of unfortunate circumstances.
"My dream never died and never went away. I was just waiting for an opportunity. I have it and I've been living my dream the last couple of years. Every match I win now it's like winning an entire tournament.
"I was really lucky and blessed to be so good when I was so young. I grew up winning since I was six years old and it was always normal. But once that was taken away for years it's incredible; every match gives me such satisfaction.
"It's almost like walking blind for years and really struggling a lot to finally be free again and reminding myself of the old ways and how good I can play and that I can play with these girls and beat them."
Former champion Maria Sharapova recovered from losing the first set to beat Australia's Jarmila Groth 4-6 6-3 6-1 in a match which ran over into the evening session.
"I knew I had a tough first-round opponent, she's been playing some really good tennis," a relieved Sharapova said. "She came out firing and did not give me many opportunities and I just hung in there and fought and those are the matches you want to get through."
Elsewhere, former champion Svetlana Kuznetsova needed three sets to beat Japanese veteran Kimiko Date Krumm, the 11th seed eventually winning 6-2 4-6 6-1.
It took until 4:45pm local time on the second day for the first female seed to lose, China's Li Na going down in three sets to Kateryna Bondarenko.
Li, who reached the semi-finals of the Australian Open earlier this year and was seeded eighth here, won the first set 6-2 but Ukrainian Bondarenko hit back to win the next two 6-4 6-2.