PARIS, France - Petra Martic matched her career-best French Open result with her best-ever win on Friday.
The No.31 seed upset No.2 seed Karolina Pliskova in the third round on Court Philippe Chatrier, 6-3, 6-3.
Martic entered Friday's match with a 13-2 record on clay this season, tied for the tour lead in wins, and scored her fourth career Top 10 win with the victory.
The Croatian's blend of topspin and variety absorbed Pliskova's power game over the course of 86 minutes, as she broke the big-serving former World No.1 five times.
"The key was to focus on my game and try to dictate instead of letting her dictate, which is her biggest strength," said Martic.
"I had to kind of try to take it away from her, and at times it was difficult, especially when she broke me and when she got a few winners, which she's known for. I'm just happy that I managed in the end to hold my nerves and to finish it off."
Martic was a perfect 5-for-5 at the net, and carved out 13 winners - and kept her calm throughout most pressure moments, including in the second set.
The 28-year-old moved ahead 6-3, 2-0, only to see Pliskova win three straight games to fall behind by a break. She nonetheless steadied against Rome champion to win the next three herself, but saved three break points in the match's final game to seal her first-ever win against a player ranked World No.3 or higher.
Martic had been 0-8 in her career against players in that ranking bracket, but all eight of those previous meetings came on hard courts.
"Of course 6-3, 6-3 is not something I was hoping for today. I think she played well. For sure I could do better," Pliskova said in defeat.
"Actually, I think the score was closer than it really was in the end, so I think I had some chances couple games, I should definitely not lose couple of serves in the first set when I was up in the games. She just made it difficult today for me.
"We played in Miami, so I think hard court is a little bit different to play her on hard court. I think it's better for me. Obviously, she's playing well this year, especially on clay. She won a title so she's playing confident.
"She was serving well. She just sometimes went for her shots and then she was patient. I think on clay it's just too difficult always to just go for it.
"My serve wasn't really working. I don't think she did much wrong today, so I think she played clever. She was patient. I just did too many mistakes."
Martic reached the round of 16 at a Grand Slam for the fifth time in her career and third at Roland Garros, which includes twice in the past three years.
The No.31 seed is guaranteed an unseeded foe to reach her first career Grand Slam quarterfinal, as she will next face five-time Grand Slam quarterfinalist Kaia Kanepi, or Russian Veronika Kudermetova, who conquered Caroline Wozniacki in the first round.
"I don't know if Roland Garros has special relationship with me, but I have it with Roland Garros. I really love this tournament. I love this surface. I really feel great here, and I hope for the first time I'll be able to make the step further," said Martic.
"I just go from one match to another, and, since I came back, I stopped looking at the draw. I just know my next opponent, and that's it.
"I think that's the only way you can kind of keep your focus and keep your calm and perform."