Thursday is the day tennis changes at full speed. Quarterfinal spots are up for grabs at the Credit One Charleston Open today, with round of 16 action featuring top seeds Aryna Sabalenka, Paula Badosa and Karolina Pliskova, as well as 2019 champion Madison Keys.No. 4 seed Ons Jabeur and No. 7 Leylah Fernandez will also take the court, but second-round matches will end after being delayed due to inclement weather on both Tuesday and Wednesday. Jabeur is one match away from victory against local hopeful Emma Navarro.Credit One Stadium’s lineup is similar to a late-stage Grand Slam day: No. 1 Sabalenka opens a …