Iga Swiatek will open the defence of her Stuttgart Open title against Qinwen Zheng after the world number 25's 6-4 6-4 win over Alycia Parks on Monday.

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.

Ons Jabeur, who claimed victory at the Charleston Open earlier this month, kicks off her tournament on Wednesday.