Third seed Garbine Muguruza won a tricky encounter with Svetlana Kuznetsova in a French Open first-round match between two former champions.
After a 90-minute rain interruption at 5-5 in the first set, Wimbledon winner Muguruza triumphed 7-6 (7-0) 6-2.
Kuznetsova of Russia, who won the title in 2009, pushed the Spaniard hard but was undone by the 2016 champion's attacks at the net.
Day three features other ex-champions Serena Williams and Maria Sharapova.