The meeting lasted 1 hour and ended with a score of 6: 2, 6: 1 in favor of the Canadian tennis player.
Potapova performed three aces and made five double mistakes.
In the second round, Fernandez will play with either Frenchwoman Oceane Doden or American Madison Keys.
Earlier it was reported that the organizers of Roland Garros may disqualify Osaka for refusing to communicate with the press.