With Johanna Konta losing later in the day, it means Heather Watson is the only one British woman left in the second round in Paris.
Highlights: Robson outclassed by Petkovic
Robson will need a wildcard to qualify for Wimbledon. She is ranked at 329 in the world due to a series of injury problems, but was forced to use a protected ranking of 58 to play in this match.
Robson threw in 37 unforced errors in 16 games in her first match since 2013 at Roland Garros.