No.3 seed Simona Halep takes on Tatjana Maria today - but unusually, it's the World No.102 who leads the head-to-head 2-0. Maria's victories both came in 2009, when she went by the name Tatjana Malek, over a 17-year-old Halep in ITF events in Monzon, Spain and Makarska, Croatia.
Karolina Pliskova is looking to go beyond the second round at Roland Garros for the first time in six attempts. Her previous second round losses came to Agnieszka Radwanska and Andreea Mitu in 2014 and 2015.
No.17 seed Anastasija Sevastova has held match point in both her meetings against Eugenie Bouchard, whom she faces for the third time today. The Canadian fought one off in Doha in 2016, winning 5-7, 6-3, 7-6(4), but the Latvian finished the job in Mallorca later that year 6-3, 6-3.
Magdalena Rybarikova is known to prefer fast courts - but her results at Roland Garros have been the most consistent of any Slam. Today, she plays the second round for the seventh time in her career.
When 20-year-old Daria Kasatkina and 17-year-old qualifier Marketa Vondrousova face off today, it will be the first senior meeting between the two. But they have history - right here, in fact. Kasatkina beat Vondrousova 6-2, 4-6, 6-4 in the semifinals of the junior event in 2014 - and went on to win the title.
Alizé Cornet is playing her 13th consecutive Roland Garros - and this is the tenth of those in which she has won at least one match. The French player's first win came on her debut in 2005 as a 15-year-old wildcard, over Alina Jidkova, and her best showing was a fourth round in 2015.
Defending quarterfinalist Tsvetana Pironkova's first-round win over Mona Barthel snapped a losing streak of seven, stretching back to Doha qualifying in February - a period in which the Bulgarian had won just one set.
Marketa Vondrousova's first round win over Amandine Hesse extended her winning streak to nine, and was her 51st victory of 2017.
Sorana Cirstea already has a Slam win in 2017 over No.21 seed Carla Suárez Navarro, her opponent today - the Romanian beat the Spaniard 7-6(1), 6-3 in the second round of the Australian Open. Indeed, Cirstea holds a 4-1 lead in the head-to-head stretching back to the pair's ITF days in 2006; Suárez Navarro's sole victory came in the semifinals of Marbella in 2009.
Qualifier Alison Van Uytvanck is making her first appearance at Roland Garros since her surprise quarterfinal run in 2015 - the Belgian was forced to miss last year's event due to injury and fell out of the Top 100. A deep run here could restore her ranking to that level for the first time since losing those points.
Madison Keys will be looking to keep her eight-Slam streak of winning at least two matches going. It stretches back to the Australian Open in 2015, at which the American made her first Slam semifinal (but excludes this year's Australian Open, which she missed due to injury).
Three women in action today are seeking to make the third round of a Slam for the first time in their career. Ekaterina Alexandrova, Magda Linette and Veronica Cepede Royg are all in a Slam second round for the second time in their careers, while wildcard Chloe Paquet is a Slam debutante.
Serena Williams was back at Roland Garros yesterday taking the role as cheerleader for sister Venus, who celebrated her second-round win with an impromptu Destiny's Child karaoke courtside.
Meanwhile, Serena's star power was demonstrated by her inclusion in ESPN's World Fame 100. The Australian Open champion is joined by Maria Sharapova, Caroline Wozniacki and Eugenie Bouchard, who plays at Roland Garros today.
And yesterday, Ons Jabeur made history by becoming the first Arab woman to make the third round of a Slam. Find out how she deals with life as a professional athlete during Ramadan in the WTA Insider Notebook - and read an open letter to her on Sport 360 by compatriot Selima Sfar, the only Arab woman to have made the Top 100 to date.
Elina Svitolina has installed herself as a title contender here with victories in the Dubai and Rome Premier 5 tournaments this year. Here's a reminder of how she won them.