Stuttgart champion Swiatek to meet Zheng in second round

Lucky loser Parks hit eight aces but also 11 double-faults and was undone once in each set as Zheng took a straight-sets victory to tee up a second-round clash with the world number one.

Cristina Bucsa came up with a third-set bagel to join Zheng in round two, having initially made hard work of fellow qualifier Tamara Korpatsch in her 3-6 6-4 6-0 win.

Bucsa will meet the winner of the clash between seventh seed Daria Kasatkina and last year's semi-finalist Paula Badosa.

Meanwhile, Donna Vekic will take on either Karolina Pliskova or Maria Sakkari after she battled to a 7-6 (9-7) 7-6 (7-5) triumph over Ekaterina Alexandrova.

The star-studded line-up sees grand slam winners including Emma Raducanu, Barbora Krejcikova and Jelena Ostapenko get their campaigns underway on Tuesday.