( CNN ) -- Four-time grand slam champion Kim Clijsters made a successful return from injury by defeating world number one Caroline Wozniacki in an exhibition match in Antwerp , Belgium . Clijsters , U.S. Open champion in 2005 , 2009 and 2010 , has been out for almost four months after sustaining a stomach muscle injury in August . `` So far , and today , everything felt really great , '' the 28-year-old said told the 10,000-strong crowd after winning 6-2 7-6 ( 7-5 ) at the Antwerp Sports Palace on Thursday . The Belgian will now focus on preparing to defend her Australian Open crown in Melbourne in January after securing victory in one hour and 35 minutes . Clijsters climbed to the top of the world rankings in February before sustaining shoulder and ankle injuries in April . She injured her stomach while attempting to recover in time to challenge for a fourth U.S. Open title and is only now regaining full fitness . `` I am happy to have played a match and break the rhythm of daily training , '' the 41-time WTA Tour winner said . Clijsters initially retired from tennis in 2007 to concentrate on raising her daughter , but in 2009 she performed a u-turn and announced she would return to sport . It was a spectacular comeback as Clijsters gained wild-card entry to the U.S. Open before going on to win the title at Flushing Meadows two years in a row . However , the Australian Open draw will be missing Sweden 's former world No . 4 Robin Soderling , who has confirmed his absence from the 2012 season 's first grand slam . The two-time French Open finalist contracted the virus infectious mononucleosis in September , but his recovery has taken longer than initially anticipated . `` I am feeling better with each day but it will still take some time before I can start practicing in full speed , '' the 27-year-old said via his official Twitter account . `` My goal is to start with practice in January and I hope for tournament comeback in February , but at this stage it is hard to know when and where . `` I hope my body will allow me to do that . I will try to give you more updates . I love reading your messages and appreciate your support and encouragement very much . '' Soderling has not played since defeating David Ferrer to win the Swedish Open on home soil in July , but still finished the year ranked 13th .
No.1 Caroline Wozniacki beats world No.1 Caroline Wozniacki on her return from injury . 6 -time grand slam winner Clijsters scored a Four -2 7-6 ( 7-5 ) success . The pair faced each other in an exhibition match in Antwerp , Belgium on Thursday . Sweden 's No.1 Caroline Wozniacki will miss January 's Australian Open due to long-term illness .