Prague - Unseeded Katerina Siniakova of the Czech Republic has upset sixth-seeded Irina-Camelia Begu of Romania 6-3, 6-3 on Monday to advance to the second round of the Prague Open.
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.
Also fifth-seeded Alize Cornet of France made the second round of the tournament by defeating wild-card entry Kristina Schmiedlova of Slovakia 6-3, 6-3.
Cornet plays Denisa Allertova of the Czech Republic, who upset Coco Vandeweghe of the United States 6-4, 6-1.
In their first encounter on the WTA tour, the 103rd-ranked Czech didn't face a break point in the first set and dominated the second against her 37th-ranked opponent.