PARIS, France - Could her semifinal showings in Acapulco and Estoril been foreshadows of what was to come at the biggest clay court tournament on the calendar? Swedish No.1 Johanna Larsson pulled off one of the biggest upsets so far at the French Open on Tuesday afternoon, coming back from a second set blankout to beat No.20 seed Ana Ivanovic over on Court Suzanne Lenglen.

The 22-year-old Larsson, whose only previous Grand Slam match victory came at this tournament a year ago, hung tough at the end of a tight first set, saving four set points - two at 4-5, two at 5-6 - before taking it in a tie-breaker. She was blown away in a 25-minute second set but rebounded to win, 76(3) 06 62.

"Even though I lost the second set 6-0, we were still at the same pace, so to speak. I had one set and she had one set," Larsson said. "I just tried to forget about it quickly and think positively. I was thinking about how nice it was to play in that big court with such a nice crowd. I was trying to get help from them."

Larsson had her first Top 10 win over Li Na in Miami this year, but said this was up there too. "It's the first time I've beaten such a high-ranked player in a big stadium with this kind of crowd; in that way it might be my biggest win."

Ivanovic, one of three former French Open champions in this year's field, was disappointed. "I felt like I was running out of power in the end and couldn't dominate with my forehand. I couldn't really put that extra zip on the ball," Ivanovic said. "It's tough, but that's how it is sometimes. I'm very upset I lost."

Speaking of Li, the No.6-seeded Chinese made it past Barbora Zahlavova Strycova, 63 67(6) 63. Li had a 5-2 lead in the second set and double match point in the ensuing tie-break but ended up going the distance to close it out.

"First match is either easy or tough, nothing between - and in a Grand Slam everyone is fighting a lot," Li said. "When I played her in Melbourne it was an easy win, but that didn't mean anything this time. It was a tough match - I was actually cramping at the end of it and hoping she couldn't see that!"

While Ivanovic and Li had battles on their hands, No.7 seed Maria Sharapova had little trouble in her match with Mirjana Lucic, winning 10 straight games from 2-3 in the first set to defeat the renewed former teen phenom, 63 60.

"It was a tough beginning because she started off serving really big and I didn't get too many looks on second serves," Sharapova said. "Once I got a good rhythm I felt like I started playing better and better. It was a good start - first rounds are tricky, especially when you don't know your opponent too well."

In the late 1990s, particularly after reaching the semifinals of Wimbledon in 1999 - where she fell to Steffi Graf - Lucic was touted as one of the big future stars on the WTA. Off-court problems plagued her career and now, at age 29 and back in the Top 100, she's back playing consistently on the tour.

"I had never faced her and we've never practiced together, but we have seen a lot of each other growing up at the academy in Florida," Sharapova said of the Croat. "She was already a professional and I was still training there. During her time off when she didn't play for a while I still saw her a lot because she lived close to the academy. We would always bump into each other but we didn't know each other that well. I knew she's had great results and she can play."