Triumphant Siniakova felt Osaka was vulnerable
Naomi Osaka's struggles early on at the French Open boosted Katerina Siniakova's confidence in being able to end the world number one's quest for a third straight major.
US Open and Australian Open champion Osaka had to come from a set down to beat Anna Karolina Schmiedlova and Victoria Azarenka in her opening two matches at Roland Garros.
The 21-year-old was unable to repeat the feat against Siniakova – the top-ranked doubles player – and fell to a 6-4 6-2 defeat on Court Suzanne-Lenglen on Saturday.
It was the Czech's first win against a top-three player but she felt Osaka, who admitted to feeling tense due to entering the tournament as world number one, was vulnerable before they stepped on court.
"I felt there was a chance, because her first and second round was tough, so I could see that she's not so confident like she was," said Siniakova.
"I just tried to focus on my game and be ready for a big fight. But I felt there was a chance.
"I can say she's more aggressive than me. It's her game. I was trying to chase every ball and make her miss if it's possible, just try to keep her behind the baseline and not feel confident.
"I think it was really good and it was working and I think her serve today wasn't so good."