Defending champion Ostapenko out of French Open in first round
Latvia's fifth seed Jelena Ostapenko became only the second defending champion to lose in the first round of Roland Garros.
Russia's Anastasia Myskina was the only other defending champion to lose in the first round in the Open era in 2005.
Kozlova, the world number 66, will face either former world number one Victoria Azarenka or Katerina Siniakova of the Czech Republic for a place in the last 32.
