French Open champion Li Na retired with a sore back against Tsvetana Pironkova in the second set of her opening match at the Open GDF Suez Tuesday. The third-seeded Li took a medical timeout while trailing 7-6 (5), 3-2 to have her lower back massaged by a physio and played a couple more points before retiring. “I was feeling my back ... It was so painful,” Li said. “That's why I called the physio to come to the court. I tried to tape and then tried to play the point, but it didn't work. “I'll go to the hospital to take an MRI to see what happened.” Li rallied from a 5-0 deficit to force a tiebreaker but she then double-faulted at 3-2 to give Pironkova a mini-break. The unseeded Bulgarian took the first set on a forehand error from Li before jumping out to a 3-1 lead in the second. “I played last week in the Fed Cup in Israel, I played some good matches which helped for my form and for my confidence,” Pironkova said. “So I felt pretty good coming here and I'm glad I could show it on the court today against such a world class player.” German qualifier Mona Barthel and Petra Cetkovska of the Czech Republic also advanced to the second round. Barthel eased past Barbora Zahlavova Strycova of the Czech Republic 6-3, 6-2, and Cetkovska beat Italian lucky loser Alberta Brianti 6-3, 6-3. Fourth-seeded Jelena Jankovic withdrew Tuesday because of a left thigh strain she picked up in Serbia's 3-2 win over Belgium in the Fed Cup last week. “I was playing against (Kirsten) Flipkens and during one point in the second set, I felt a really sharp pain, but I managed to finish the match,” Jankovic said. Russia's Maria Sharapova, the Australian Open finalist, and France's Marion Bartoli, are the big names remaining in the tournament and open their campaigns in the second round midweek. Zvonareva makes fine start In Pattaya, Thailand, Vera Zvonareva began her quest for a third Pattaya Open title by putting away local qualifier Varatchaya Wongteanchai 6-2 7-5 Tuesday. The only bother for top-seeded Zvonareva was when she faced three break points at 5-5 0-40, but summoned powerful serves to get off the hook and win the last two games. “The first match is always tough,” said Zvonareva, the 2009 and 2010 champion. “I didn't play my game but I always came up with better shots when I needed them.” The Australian Open doubles winner moved on to meet Akgul Amanmuradova of Uzbekistan, who beat Laura Robson when the Brit retired 5-2 down. Eighth-seeded Vania King of the United States tamed Heather Watson of Britain 6-4, 6-2, but No. 6 Galina Voskoboeva of Kazakhstan retired sick while trailing Thai veteran Tamarine Tanasugarn 6-3, 4-2. Also, Misaki Doi of Japan beat wild card Noppawan Lertcheewakarn 6-1, 6-3, Alla Kudryavsteva of Russia beat qualifier Zhou Yi-Miao of China 6-1, 7-5, and qualifier Chang Kai-chen of Taiwan downed Eleni Daniilidou of Greece 7-5, 6-1.
