Top seeds Li Na and Marion Bartoli posted straight-set wins Wednesday in second-round action of the Shenzhen Gemdale Open tennis tournament in China. Li, No. 7 in the world and the top seed in Shenzhen, got by Julia Cohen 6-3, 6-4 despite five double faults and losing her serve three times. She did manage five breaks in nine receiving games, however, and won more than half of the points when Cohen served. Bartoli, the second seed, defeated Stefanie Voegele 7-5, 6-4. Bartoli committed nine double faults and dropped serve four times. But she also won 50 percent of the points when receiving serve and had three breaks in each set. China\'s Zhou Yi-Miao, No. 177 in the world, was a 4-6, 6-2, 7-6 (7-3) winner over Chang Kai-Chen in Wednesday\'s other match. Chang hampered herself with 12 double faults. Source:UPI