Zheng Saisai, the Chinese player who surprisingly knocked out Australian Open champion Angelique Kerber from the Qatar Open, claimed another high-profile scalp Wednesday, beating Eugenie Bouchard in straight sets. Zheng, 22, won 7-6 (7-1), 6-1 to march into the final eight in Doha. The world No. 73 won in an hour and 35 minutes against Bouchard, who is returning to the circuit from a freak injury she sustained at the US Open last September. Zheng's victory came just 24 hours after she dumped Kerber out with a 7-5, 6-1 win. After Tuesday saw seven seeds knocked out, the surprises continued Wednesday. Among the early losers was the No. 5 seed and double Wimbledon champion Petra Kvitova who was defeated by Latvia's Jelena Ostapenko, 5-7, 6-2, 6-1. Ostapenko is ranked 78 places behind world No. 8, Kvitova. In other results: Agnieszka Radwanska of Poland beat Monica Niculescu of Romania 7-5, 6-1; Carla Suárez of Spain downed Timea Bacsinszky 6-2, 6-2; and Elena Vesnina of Russia beat Caroline Wozniacki of Denmark 7-5, 5-7, 6-3. Captain Hewitt backs Kyrgios, Tomic against USA Australia's Davis Cup captain Lleyton Hewitt is backing young guns Nick Kyrgios and Bernard Tomic in the upcoming tie against the United States but stressed it will be tough. Tomic and Kyrgios were Tuesday announced as part of the Australian team which also includes Sam Groth and doubles specialist John Peers to play the World Group first round tie on March 4-6. "I believe in both of them," Hewitt said of world No. 21 Tomic and Kyrgios, who won his first ATP title at the Marseille Open on Sunday. "I think the match-ups can work in our favor. But it's going to be tough tennis, you know and pressure and expectation always plays a massive part in Davis Cup," the former world No. 1 said. "But Bernie, in particular, has got a really good Davis Cup record and it's taken absolute quality players and quality tennis to beat him in Davis Cup." USA captain Jim Courier has announced John Isner, Jack Sock and twins Bob and Mike Bryan on his roster for the event at Kooyong, Tennis Australia said Wednesday.
