Belgium Fed Cup team for the 2003 Fed Cup's semifinal opposing the United States. She played her first Fed Cup match against then WTA No. 17, Meghann Shaughnessy and lost 7–6, 6–7, 7–9. She finished 2003 as world No. 1 of the junior rankings in both singles and doubles. At the end of the year, she was awarded Best Belgian Talent and named ITF Junior World Champion. Professional career 2001–08: First steps, problem with injuries Flipkens played her first professional match on the ITF Women's Circuit in 2001 at the age of 15. Next year, she won her first ITF singles title at a $10k event in Pétange, when she defeated German qualifier Tanja Hirschauer, and two weeks later another $10k title in Koksijde. The following year, Flipkens made her debut at the WTA Tour, at the Diamonds Games in Antwerp, but finished her participation at the beginning of the tournament. 2004 was the first year when she attempted to qualify in Wimbledon into the main draw of a major. After a first-round loss at the Gaz de France Stars in September, Flipkens stated that she struggled with a congenital back injury during the second half of 2004. She was unable to play for several months. She made her return at $50k event in Saint-Gaudens in May 2005, but lost in her first match. In late May, she made her debut in the qualifying of the French Open. Later, she also failed in qualifying for Wimbledon and the US Open. In 2006, Flipkens made big steps further, reaching the main draws at the French Open, Wimbledon and the US Open. At the French Open, she recorded her first Grand Slam match win, defeating qualifier Virginie Pichet, but lost in the next round to Flavia Pennetta. At the US Open, she got to the same stage of tournament, falling to eventual semifinalist Jelena Janković, while at Wimbledon, she lost in the first round. She also partnered with British No. 2, Andy Murray, in mixed doubles at Wimbledon. Flipkens started 2007 season with modest results, including only first rounds at the Australian Open and Diamond Games. In May, she stated that she suffered from a wrist injury, which resulted in not being able to play for several months. She returned in September, playing mostly at the ITF Circuit, with reaching only one final at the $50k event in Deauville, where she lost.