Top seed and 2016 French Open champion Novak Djokovic continues his bid to hold all four Slams at once for the second time in his career on Thursday.
Naomi Osaka, who was just two points from defeat in her opener, faces another minefield in the form of former world number one and two-time major winner Victoria Azarenka.
Three-time winner at Roland Garros, Serena Williams is looking to win a record-equalling 24th major and she faces Japanese qualifier Kurumi Nara in the second round.
Naomi Osaka (JPN x1) v Victoria Azarenka (BLR)
US and Australian Open champion Osaka was just two points away from a shock defeat in the first round against world number 90 Anna Karolina Schmiedlova who served for the match twice in the second set.
READ| Osaka: First-round scare most nervous I've ever been on court
“I think this was the most nervous I have ever been my entire life during a match,” said 21-year-old Osaka after that match.
Azarenka, now ranked 43 in the world, knocked out 2017 champion Jelena Ostapenko in the first round and was a semi-finalist in Paris six years ago.
She came into the French Open with solid clay court form having made the quarter-finals in both Stuttgart and Rome.
Azarenka won the first meeting between the two at the Australian Open back in 2016 but the Japanese star levelled the proceedings, dropping just three games in a second round win on clay in Rome last year.
Novak Djokovic (SRB x1) v Henri Laaksonen (SUI)
Head-to-head: First meeting
Djokovic eased through his opener in straight sets against Poland's Hubert Hurkacz as he bids to become only the second man to hold all four Slams simultaneously for a second time.
READ| Djokovic up and running in 'Novak Slam' pursuit
The top seed faces Swiss lucky loser Laaksonen who has made the second round of a major for the first time.
The Finland-born world number 104 recently conquered a debilitating allergy to seafood despite having eaten fish virtually every day for all of his adult life.
“I don't know too much about him, to be honest,” said Djokovic ahead of the match.
“I never played against him, and I did watch him play maybe once or twice. I'm going to have to do my homework and see what happens.”
Serena Williams (USA x10) v Kurumi Nara (JPN)
Head-to-head: First meeting
Three-time champion Williams looked rusty in her opener against Vitalia Diatchenko where she dropped the first set.
The American, who is attempting to equal Margaret Court's all-time record of 24 Grand Slam titles, racked up her 800th main draw win of her career in a match which saw her unveil her 'mother, champion, queen, goddess' logo on her playing gear.
On Thursday, she faces world number 238 Kurumi Nara who stands at just 5ft 1in (1.75m) tall but can mix it up with the best of them.
In the 2017 US Open, she ruthlessly demolished a former multiple-time grand slam winner Svetlana Kuznetsova.
The 27-year-old Nara, who has reached a career-best ranking of 32, came through qualifying and is hoping to make the third round at Roland Garros for the first time ever.