Nao Hibino of Japan eliminated top seed Beatriz Haddad Maia of Brazil 7-6, 6-3, while Valeria Savinykh of Russia topped second seed Magda Linette of Poland 7-5, 3-6, 7-6.
German Laura Siegemund defeated home-country favorite Xinyu Wang, the fourth seed, 6-1, 7-5, and Xiaodi You of China cruised past sixth seed Anna Blinkova of Russia 6-1, 6-1.
Also advancing were third seed Marie Bouzkova and her fellow Czech, Katerina Siniakova. French seventh seed Varvara Gracheva, Leylah Fernandez of Canada, Norway's Ulrikke Eikeri and Aliaksandra Sasnovich of Belarus also moved to the second round.
Transylvania Open
Eva Lys of Germany surprised top-seeded Sorana Cirstea of Romania 6-3, 6-3 in just 72 minutes in the first round in Cluj-Napoca, Romania.
Lys won 31 of 51 first-service points (60.8 percent) and converted six of her seven chances to break Cirstea's serve.
The second and third seeds also bowed out. Romanian Elena-Gabriela Ruse beat second seed American Alycia Parks 6-2, 1-6, 6-4, and Ukraine's Daria Snigur upset third seed Greet Minnen of Belgium 6-3, 6-2 in only 65 minutes.
Fifth seed Ana Bogdan of Romania, Colombia's Emiliana Arango, Hungary's Anna Bondar and Germans Tamara Korpatsch and Anna-Lena Friedsam also advanced.
Jasmin Open Monastir
Top seed Jasmine Paolini of Italy cruised past France's Alize Cornet 6-4, 6-2 in opening-round action in Monastir, Tunisia.
Paolini both saved five of seven break points and converted five of seven opportunities to break Cornet's serve as she eased to the second round to face Croatian Petra Marcinko, who was a 7-6, 6-2 winner over Spain's Marina Bassols Ribera.
Number two seed Elise Mertens of Belgium also won, beating Alexandra Eala of the Philippines 7-5, 6-0, while third-seeded Italian Martina Trevisan fell to Poland's Katarzyna Kawa 6-3, 3-6, 7-5.
Other winners included number four seed Lesia Tsurenko and Katarina Zavatska of Ukraine, number six seed Lucia Bronzetti of Italy, Russia's Erika Andreeva, Japan's Mai Hontama, Nuria Parrizas Diaz of Spain and American Claire Liu.
