Kerber’s preparations for Roland Garros, where she never advanced past the quarterfinals, were hampered by the injury she suffered at the Madrid Open last month.
The 81st-ranked Potapova sealed the opening set with a crosscourt backhand winner and broke twice at the start of the second. Kerber saved two match points before shanking a forehand wide sealing her fate. Among other seeded players in action, 2016 champion and 19th-seeded Garbine Muguruza advanced to the second round with a 5-7, 6-2, 6-2 win over American Taylor Townsend at the tournament’s newest stadium, Court Simonne Mathieu. No. 11-seeded Marin Cilic of Croatia defeated Thomas Fabbiano of Italy 6-3, 7-5, 6-1.