Two-time Grand Slam champion Svetlana Kuznetsova was eliminated in the first round of the Prague Open on Monday on a day of upsets.

The fourth-seeded Kuznetsova lost 6-4 6-3 to Shuai Zhang, the Chinese player’s first win over the Russian in five meetings.

Another unseeded player, Katerina Siniakova of the Czech Republic, upset sixth-seeded Irina-Camelia Begu of Romania 6-3 6-3 to advance to the second round.

The 18-year-old Czech will play Polona Herzog of Slovenia, who overcame Heather Watson of Britain 7-5 3-6 7-6 (5) in a match that took more than three hours.

Flying the flag for the seeds was Frenchwoman Alize Cornet, the fifth seed advanced to the second round with a 6-3 6-3 victory over Kristina Schmiedlova of Slovakia.

Cornet plays Denisa Allertova of the Czech Republic, who upset Coco Vandeweghe 6-4 6-1.

Eighth-seeded Camila Giorgi of Italy was also eliminated, losing 6-4 3-6 5-7 to Yanina Wickmayer.