She was not seeded at tournaments in Indian Wells and Miami, and compiled two wins and two losses.
Looking a shadow of the player who won the title in Paris three years ago, Wawrinka struggled with his serve and hit an very bad lot of unforced errors (72) in his 6-2, 3-6, 4-6, 7-6 (5), 6-3 loss.
Williams won the French open singles title in 2002, 2013 and 2015.
All in all, it was quite a Day 1 at the only Grand Slam site that gets things started on a Sunday.
After losing in the qualifying tournament, Safwat had been put on the so-called "lucky loser" list of players, who are given the chance to enter the main draw in case of a withdrawal. He faced Bernard Tomic in the first round on Monday and emerged with a 6-4, 5-7, 6-4, 6-4 victory in a match that lasted almost 3 hours.More news: Warriors glad to be back in Texas for Game 7
Having taken the second set to level the match, Cornet then double-faulted on serve to gift Errani a break at the start of the third.
Sloane Stephens ended her grand slam drought since winning the US Open last summer with a 6-2, 6-0 win over lucky loser Arantxa Rus of the Netherlands on the new Court 18.
The French tennis federation did not respond to a request for comment. Tsonga, Monfils and Gasquet are all now ranked outside the world's top 30, with Pouille the French number one at 16th.
Kvitova's best run in Paris was to the semifinals in 2012.
Playing at Roland Garros with a wild card, 19-year-old Frenchman Corentin Moutet defeated veteran Ivo Karlovic 7-6 (7), 6-2, 7-6 (5) to reach the second round.
Serena Williams is now ranked No. 453 in the world. She made 29 unforced errors in the first set.More news: Congressman compares National Football League anthem protests to Nazi salutes
The 21st-seeded Kyrgios pulled out with an injured right elbow on Sunday.
Kyrgios was seeded 21st and would have faced Bernard Tomic in an all-Australian matchup in the first round. EPA/CHRISTOPHE PETIT TESSONTaylor Fritz of the US in action against Guido Andreozzi of Argentina during their men's first round match during the French Open tennis tournament at Roland Garros in Paris, France, 27 May 2018. He has lost only one match on his favorite surface this season, claiming titles in Monte Carlo, Barcelona and Rome.
The top-ranked Spaniard faces Simone Bolelli of Italy on Court Philippe Chatrier. On Monday, she learned that her path to a French Open title will be harder than it could have been, if French Open organizers chose to give her a seeding.
Jo-Wilfried Tsonga looked a certain future Grand Slam champion when he burst onto the scene by beating both Murray and Nadal en route to an Australian Open final defeat by Novak Djokovic in 2008, but he has never scaled such heights again since.
Current rules covering maternity leave and injuries allow a protected or "special" ranking to be utilised for entry into tournaments but not for seeding purposes regardless of the reason for a player's absence.More news: Record travel numbers and gas prices this Memorial Day weekend