PARIS, Feb 8: French Open champion Li Na retired with a sore back in the second set of her opening match at the Paris Open against Tsvetana Pironkova here on 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 stated. “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.”

Petra Cetkovska of the Czech Republic, Petra Martic of Croatia and Chanelle Scheepers of South Africa also advanced to the second round along with three German players — Julia Goerges, Angelique Kerber and Mona Barthel.

Goerges cruised past Shahar Peer of Israel 6-1, 6-3.

The sixth-seeded German won nine straight games to take the first set and go 4-0 up in the second.

Kerber beat Lucie Safarova of the Czech Republic 6-2, 7-6 (3).

A two-time finalist at this tournament, Safarova served seven double-faults and made numerous unforced errors.Kerber broke Safarova twice in the first set. The US Open semi-finalist then won five straight points to lead 5-1 in the tiebreaker, clinching victory when Safarova’s backhand return sailed long.

Scheepers ousted Polona Hercog of Slovenia 6-2, 6-2, Barthel eased past Barbora Zahlavova Strycova of the Czech Republic 6-3, 6-2, Cetkovska defeated Italian lucky loser Alberta Brianti 6-3, 6-3, and Martic beat Greta Arn of Hungary, 6-4, 6-4.

Fourth-seeded Jelena Jankovic withdrew on 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 remarked.

Results: First round: Petra Martic (Croatia) bt Greta Arn (Hungary) 6-4, 6-4; Chanelle Scheepers (South Africa) bt Polona Hercog (Slovenia) 6-2, 6-2; 6-Julia Goerges (Germany) bt Shahar Peer (Israel) 6-1, 6-3; 9-Angelique Kerber (Germany) bt Lucie Safarova (Czech Republic) 6-2, 7-6(3); Tsvetana Pironkova (Bulgaria) bt 3-Li Na (China) 7-6(5) 3-2 (Li Na retired); Petra Cetkovska (Czech Republic) bt Alberta Brianti (Italy) 6-3, 6-3; Mona Barthel (Germany) bt Barbora Zahlavova Strycova (Czech Republic) 6-3, 6-2.—Agencies