Melbourne: Serena Williams admitted she was frustrated and not at her best as she fought off a stubborn Tamara Zidansek to reach the Australian Open third round on Wednesday. The American great, one short of Australian Margaret Court's all-time record of 24 Grand Slam titles, faces China's 27th seed Wang Qiang next in Melbourne. Williams, 38, was never in serious trouble against the 70th-ranked Slovenian Zidansek, winning 6-2, 6-3 at Rod Laver Arena. But the eighth seed was restrained in her celebrations and said: "It was a good match for me, she was a really good fighter, she did not just let me win."

Zidansek, 22, put up resistance in the second set with Williams twice failing to break when 40-0 up on the Slovenian's serve. Williams then struggled through her own service game at 3-2 down, with a brief stoppage while the roof closed because of more rain in Melbourne. Williams finally broke Zidansek's stubborn resolve in the seventh game, getting the break of serve on the way to victory in one hour 18 minutes. The American great described herself as "frustrated" by her failure to bury her opponent in those two service games.