Clijsters pleased her home-country crowd of 13,000 in the match at the Antwerp Sports Palace, which was attended by Crown Prince Phillipe and Princess Mathilde.
The 29-year-old four-time Grand Slam champion played her last official match at this year's U.S. Open when she fell to Britain's Laura Robson.
Clijsters announced her retirement in May after dealing with a series of nagging injuries.
She retired once before, in 2007 before giving birth to a daughter, but returned in 2009 and won her second U.S. Open that year, then repeated in 2010.
She garnered the world No. 1 ranking in 2011 after taking the Australian Open.