Olympic Games gold medallist Monica Puig advanced to the second round of the Volvo Car Open and she was joined by former champion Jelena Jankovic.
Puig stood atop the podium in Rio de Janeiro last year and the Puerto Rican benefited from a retirement against 16th seed Katerina Siniakova before heavy rain cancelled play on Monday.
The match came to an end when Puig was leading 6-4 2-6 4-1 in the third set as Siniakova succumbed to a back injury in Charleston.
Serbian veteran Jankovic also made it through her first-round clash with Ekaterina Alexandrova.
Champion in 2007, Jankovic triumphed 6-0 6-4 after breaking serve on six occasions at the WTA Premier event, which will be without Miami Open winner Johanna Konta due to illness and a lingering shoulder issue.
There were victories for 2014 winner Andrea Petkovic, Naomi Osaka and Laura Siegemund.
Petkovic overcame Lara Arruabarrena 7-5 6-2, Osaka outlasted Johanna Larsson 6-7 (4-7) 6-4 6-2 and Siegemund prevailed 6-7 (6-8) 6-2 7-6 (7-4) over Lesia Tsurenko
Elsewhere, Kateryna Bondarenko beat Evgeniya Rodina 6-4 7-5, Ana Bogdan lost 6-4 6-2 to Jelena Ostapenko, Marina Erakovic went down 6-4 6-1 to Ons Jabeur and Alison Riske trumped Kayla Day 7-5 4-6 6-0 in their all-American affair.