PARIS, France - Former World No.9 Andrea Petkovic won just her third WTA main draw match of the 2018 season at the site of one of her biggest career triumphs, shocking 2017 French Open quarterfinalist Kristina Mladenovic, 7-6(10), 6-2.

"I think I played solid and I did what I had to do," she said after the match. "I've beaten her many times before. The thing that bothers her most about my game is that I return really well and neutralize her serve. That was difficult for me today because we're playing on clay and she has a really good kick serve.

"But I knew what I had to do, stuck with the game plan and what I know has worked in the past. There were a lot of emotions because it was an important win for me and I know it was a difficult moment for her."

The German arrived on Court Suzanne Lenglen having lost just one set to Mladenovic in four previous matches - including one at the French Open in 2014. Unseeded and ranked outside the Top 100, she nonetheless maintained that perfect record against the Frenchwoman after a thrilling opening set tie-break that saw her save four set points - three in a row from 3-6 down - and ultimately emerge victorious in one hour and 42 minutes. 

"I played against Sharapova on this court a few years ago, and it's a tough one to play on, especially when you're returning because it's as if the fans are sitting level with the players so you can lose the ball for a second. I was just trying to play point by point.

"I told my coaches, but they didn't believe me, that I didn't even realize I'd saved three set points in a row. When we had to change sides, I didn't realize it was 6-6, but I did the math because I'd won three points in a row, and that's when I realized I was down three set points."

Petkovic roared into the semifinals of Roland Garros a full four years ago - falling to eventual finalist Simona Halep - but has struggled with injuries and inconsistencies since returning to the Top 10 in 2015. She began this season with a dramatic victory over Petra Kvitova at the Australian Open, but only won one more main draw match between the year's first two major tournaments.

"When I'm at my best, I'm able to play point by point. It's no secret that I have a lot of thoughts going on upstairs, which sometimes hinders me. But I also analyze pretty well after losses. I've learned a lot from the last couple years, and I feel like a much mentally stronger player."

Against the No.29 seed, she treated the crowd to some of her best tennis as she struck 23 winners to 21 unforced errors and raced out to a 5-1 lead in the second set.

"This was an important match for me. I'd lost three heartbreakers in the first round where I didn't play awful but couldn't close it out. Here I was again, on a big court with a lot of emotions at an important tournament. I knew I'd beaten her before so I felt pressure before the match. I'm going to try and be satisfied for a day - or what's left of it - before I start thinking about what comes next."

As for Mladenovic, it has been a year of highs and lows since she dethroned then-reigning champion Garbiñe Muguruza en route to the last eight. While debuted in the Top 10 singles rankings and partnered Timea Babos to win the Australian Open women's doubles title, the 25-year-old lost 15 straight singles matches before reaching the final of the St. Petersburg Ladies Trophy in February. 

"I was expecting a difficult match, because I never found a way to win Andrea in singles," she said in press. "I think she likes the way I hit my shots. We all know what the good points and the bad points of other players, but I don't really know hers.

"You can't write the script yourself every time. I would have liked to remain here, but whatever happens, it still is my favorite tournament. I still have very good memories and very good feelings.

"Today didn't work, but I enjoyed trying to do my best and fighting as I did today. So we will try another time."

Looking to rediscover the form that thrilled her home fans a year ago, Mladenovic saved three match points in a titanic final game before Petkovic closed the door and opened up a second round clash with either Bethanie Mattek-Sands or Nürnberger Versicherungscup champion Johanna Larsson.