LONDON - Katerina Siniakova of the Czech Republic upset the fifth seed Zheng Qinwen of China in the women's singles first round at Wimbledon on Tuesday.

With 10 women's doubles Grand Slam titles in her pocket, Siniakova, 29, tried to make new breakthroughs in the singles, who showed resilience to win the first set 7-5.

After the 22-year-old Zheng bounced back to secure victory in the second set 6-4, Siniakova dominated the final set with a 5-0 start and sealed the win at 6-1.

Siniakova will confront Japan's Naomi Osaka in the second round.