NEW YORK — Back at the site of her greatest victory, Samantha Stosur looked like a champion again, not the player who has often struggled this year.
The Australian began the defense of her U.S. Open title Monday with a dominant win, needing 51 minutes to beat 64th-ranked Petra Martic 6-1, 6-1 in the tournament’s first match at Arthur Ashe Stadium before rain suspended play.
The last time Stosur played on this court, she stunned Serena Williams in the 2011 final at Flushing Meadows for her first Grand Slam title. But in so many ways, that 6-2, 6-3 victory was starting to feel as if it happened much more than a year ago.
In 2012, Stosur had lost in the first round in front of the home fans at the Australian Open. She lost in the second round at Wimbledon, then again in the first round at the London Olympics.
Sandwiched in between, she made a run to the semifinals of the French Open, but fell apart by committing 21 unforced errors in the third set of her loss to Sara Errani.
Despite her status as defending champion, Stosur, seeded seventh this year, is not considered one of the favorites coming into Flushing Meadows.
British sports books have her listed at 28-1 to repeat, same as Venus Williams, who has a 1-2 record in Grand Slams in 2012, and behind No. 4 seed Serena Williams, No. 3 Maria Sharapova, No. 1 Victoria Azarenka and four others.
On Monday against Martic, who withdrew from the Olympics with a left foot injury, Stosur had 22 winners and 10 aces and didn’t face any break points.
Other players starting Monday include third-seeded Andy Murray of Britain, coming off his Olympic gold medal at the London Olympics. He faces Alex Bogomolov Jr. of Russia. Top-seeded Roger Federer plays American Donald Young in the night session.
Also playing in Arthur Ashe Stadium are No. 3 Maria Sharapova, against Melinda Czink of Hungary, and No. 23 Kim Clijsters, opening the final tournament of her career with a first-round match against American Victoria Duval. Clijsters missed last year with an injury, but has won the tournament the past three times she’s entered — in 2005, 2009 and 2010.
The Williams sisters, No. 2 Novak Djokovic and No. 20 Andy Roddick, the 2003 champion, are among those who start later in the week.