- Reigning champion Samantha Stosur cruises through U.S. Open first round match
- Top seed Victoria Azarenka also through after a crushing 6-0 6-1 win
- Former world No. 1 Maria Sharapova and three-time champion Kim Clijsters through
- Fifth seed Petra Kvitova battles through first set tiebreak to make second round
Australian Samantha Stosur made a strong start to the defense of her U.S. Open crown with a crushing opening victory at Flushing Meadows.
Her Croatian opponent Petra Matric won just two games as the seventh seed marched to a 6-1 6-1triumph in just 51 minutes.
Stosur won the first grand slam title of her career in New York last year, beating home-crowd favorite Serena Williams in the final.
The 28-year-old will now face Edina Gallovits-Hall, an unseeded Romanian who has won through to the second round of year's final major for the first time.
Speaking after the match, Stosur explained how being away from home has helped her game.
"You're in the spotlight a bit more back home and you see yourself on TV and the newspapers even if you're not looking for it," the 28-year-old told reporters. "It's unavoidable, whereas here there are other players that are in that spotlight instead."
World No. 1 Victoria Azarenka dropped just one game against Russia's Alexandra Panova as she secured her place in the second round.
The Australian Open champion, eliminated in the third round of the 2011 event, took just 50 minutes to complete a resounding 6-0 6-1 win and set up a tie with Belgium's Kirsten Flipkens.
Olympic silver medal winner Maria Sharapova put in a powerful performance against Hungarian Melinda Czink, winning 6-2 6-2.
The 2006 champion wrapped up the match in just over an hour and will face Spain's world No. 78 Lourdes Dominguez Lino for a place in the last 32.
A two-and-a-half-hour rain break did not trouble ninth seed Li Na, as she reached the second round for the first time since 2009 with a 6-2 6-3 victory over Britain's Heather Watson. She will now play unseeded Australian Casey Dellacqua.
Three-time champion Kim Clijsters made a fine start to the final grand slam of her career, entertaining the Arthur Ashe Stadium with a 6-3 6-1 defeat of American Victoria Duval.
The Belgian, who came out of retirement in 2009 and won back-to-back U.S. Open titles, will retire after this tournament and faces Britain's Olympic mixed doubles silver medalist Laura Robson in the next round.
Fifth seed and 2011 Wimbledon champion Petra Kvitova battled past Slovenian Polona Hercog 7-6 6-1 to set up a meeting with 50th-ranked Alize Cornet of France.