Top seed Belinda Bencic's first-round tie against qualifier Antonia Lottner is a reprise of the 2013 Roland Garros girls' final, which Bencic won 6-1, 6-3. The Swiss player won two of their three junior matches, including both clay encounters, as well as a 6-3, 6-2 victory in the first round of the ITF W60 event in Croissy-Beauborg in 2017 - their only meeting at pro level. Bencic is bidding for the first WTA-level win of her career on home soil, while Lottner will be seeking her third Top 20 scalp.
Another erstwhile junior rivalry to be resumed today is that between 17-year-old Iga Swiatek and 19-year-old Katarina Zavatska. The Ukrainian won their only junior meeting 6-1, 2-6, 6-2 in the Umag Grade 1 semifinals in 2016, but Swiatek avenged that result 6-2, 6-2 in the final of last year's ITF W60 in Budapest.
No.2 seed Carla Suárez Navarro leads Polona Hercog 3-2, including 3-1 on clay. The Spaniard has won all three of their European meetings - in Marbella in 2010 and in Estoril/Oeiras in 2012 and 2014 - while Hercog has won both matches on other continents - in Acapulco in 2010 and Seoul in 2011. None of their encounters has gone to a deciding set.
Australian Open junior champion Clara Tauson made her WTA qualifying debut via wildcard this week - and has navigated through two rounds without dropping a set to extend her professional winning streak to 17 and to make her WTA main draw debut against Evgeniya Rodina. Including juniors, the 16-year-old Dane is 29-2 in 2019 so far, having won two junior events and three ITF World Tour trophies, with her only losses coming in Fed Cup play to Natalia Vikhlyantseva and Iga Swiatek.
No.5 seed Pauline Parmentier is 2-1 against home favorite Stefanie Voegele, though the pair have never played on clay before: Parmentier's wins both came in the Poitiers ITF W100 event, in 2010 and 2015, while the Swiss player captured their Australian Open first-round tilt in 2015.
ORDER OF PLAY (all courts start 10.30am)
Polona HERCOG (SLO) vs Carla SUÁREZ NAVARRO (ESP) 
[WC] Ylena IN-ALBON (SUI) vs Kristyna PLISKOVA (CZE)
Pauline PARMENTIER (FRA)  vs Stefanie VOEGELE (SUI)
CHEN Pei-Hsuan (TPE) / WU Fang-Hsien (TPE) vs [WC] Timea BACSINSZKY (SUI) / Ylena IN-ALBON (SUI)
Not before 6pm
Belinda BENCIC (SUI)  vs [Q] Antonia LOTTNER (GER)
Viktoria KUZMOVA (SVK)  vs [Q] Giulia GATTO-MONTICONE (ITA)
[Q] Reka-Luca JANI (HUN) vs Vera LAPKO (BLR) 
Evgeniya RODINA (RUS) vs [Q] Clara TAUSON (DEN)
Not before 3pm
Viktorija GOLUBIC (SUI) / Jil TEICHMANN (SUI) vs Giorgia MARCHETTI (ITA) / Arantxa RUS (NED)
Iga SWIATEK (POL) vs [Q] Katarina ZAVATSKA (UKR)
Fiona FERRO (FRA) vs Mandy MINELLA (LUX)
Rebecca PETERSON (SWE)  vs [Q] Magdalena FRECH (POL)
Not before 3pm
Mona BARTHEL (GER) / Xenia KNOLL (SUI) vs Fiona FERRO (FRA) / Pauline PARMENTIER (FRA)