Main-draw play started at the Porsche Tennis Grand Prix on Tuesday and the schedule featured six first-round matches with three German players keeping the crowd on their toes.
Seed No.6 Bertens, the highest seed in action, defeated German qualifier Anna-Lena Friedsam 7-5 6-2 for her 80th main-draw career win on clay and first in Stuttgart. The first set went with serve until the eleventh game, when Bertens finally converted her seventh break point for a 6-5 lead and then saved two break points in the following game to close out the set in 65 minutes.