The British number 1 struggled in the match against the Latvian player.
Last year, Raducanu managed to make it to the quarterfinals at Stuttgart. Since she did not finish nearly as well or better, she will drop in the ranking further to Number 68.
Ostapenko will next face Ons Jabeur as one of the last 16.
Earlier, Raducanu skipped the qualifiers for the Billie Jean King Cup in order to prepare for this tournament and the clay swing of the season.
But she did not even make it past the first round as Ostapenko had 26 winners compared to Raducanus six.
I knew against her the main thing was to step in the court, Ostapenko said.
Of course, I missed some balls but I tried to be aggressive all the time when it was possible. Just try to take the ball early, dont give her many chances. And finally, Im back on clay, my favorite surface.
Ostapenko has dropped down on the rankings in the past years but one of her best seasons was in 2017. When speaking about it, she said:
I was kind of fearless. I was not thinking too much.
I felt today a little bit that way. I was just going for the shots. Even if I was missing, I was, like, Its fine, I will still go for the shots.
Probably [need] to bring back this fearlessness, but of course, its tougher when you get older. You start to think more and of course, you want to play better and more consistently.
Since her win at the US Open, Raducanu has struggled to recapture the magic that helped her with that dream run. However, she refuses to be bowed down by the pressure to perform well.