PARIS - French Open champion Li Na of China was forced to quit her first-round match at the WTA Paris Indoor Open on Tuesday because of injuries.
Third-seeded Li withdrew while trailing Bulgarian Tsvetana Pironkova 7-6 (7-5), 3-2 at the Paris-Coubertin Stadium.

Li was visibly suffering with a back problem and finally abandoned the match after receiving treatment courtside.

Earlier Serbia's Jelena Jankovic, the fourth seed, withdrew after failing to recover from a left thigh injury she picked up during her win over Belgium Kirsten Flipkens in Serbia's Fed Cup World Group first round success last weekend.

Germany's Mona Barthel reached the second round after beating Barbora Zahlavova Strycova of the Czech Republic 6-3, 6-2 with another Czech Petra Cetkovska easing past Italy's Alberta Brianti 6-3, 6-3.