Serena Williams made a stuttering start to her bid to topple Dinara Safina from the world No. 1 spot with an error-strewn 7-5, 6-4 win over Estonian Kaia Kanepi in the first round of the China Open Sunday. Safina, who must at least match Serena's progress over the next week in Beijing to retain the No. 1 ranking, was equally unconvincing in her 6-4, 6-4 victory over Italian Roberta Vinci earlier in the day. The Australian Open and Wimbledon champion made nine unforced errors in the 83-minute encounter against the big-hitting Kanepi, who broke the second seed three times. Serena, though, always looked to have the edge on the big points and reached the second round of the $6.6-million event with a fifth break of serve when Kanepi went long, keeping alive the American's hopes of reclaiming the top ranking. Top seed Safina's victory over 59th-ranked Vinci was certainly an improvement on her first-round loss to Taiwanese qualifier Chang Kai-chen at the Pan Pacific Open last week but was by no means commanding. Broken early in both sets, Safina immediately evened up matters with breaks of her own but was then forced to scrap it out with the dogged Italian to claim victory. Fifth seed Caroline Wozniacki of Denmark suffered a first-round upset, crashing out 6-7, 7-6, 6-0 to Spain's Maria Jose Martinez Sanchez. Fourth seed Elena Dementieva, returning to the scene of her Olympic triumph last year, had no such problems with her opening match and dispensed with Germany's Anna-Lena Groenefeld 6-4, 6-0 in just over an hour. Dementieva's sixth-seeded fellow Russian Svetlana Kuznetsova started the day by damaging hopes of a first local champion with a 7-6, 7-5 defeat of China's number two Zheng Jie. In other first round matches Sunday, Russian seventh seed Vera Zvonareva beat Romania's Sorana Cirstea 6-2, 6-2, and Switzerland's Patty Schnyder got past Poland's Urszula Radwanska 6-4, 7-5. Ninth seed Victoria Azarenka of Belarus advanced, easily defeating compatriot Olga Govortsova 6-1, 6-3. The men's main draw gets under way Monday, with Rafael Nadal, Novak Djokovic and Andy Roddick leading the charge. Davydenko wins Malaysia Top-seededed Nikolay Davydenko of Russia beat Fernando Verdasco of Spain 6-4, 7-5 to win the Malaysia Open Sunday. Davydenko's third straight win extended his record to 6-1 over Verdasco and gave him a third title this year. He has also won the German Open in Hamburg and Croatia Open in Umag. Simon claims title In Bangkok, Frenchman Gilles Simon claimed his first title of the year after a 7-5, 6-3 win over Serbian Viktor Troicki in the Thailand Open Sunday. The pair were evenly matched throughout the one hour, 15 minute encounter but it was the Serbian's mistakes that ultimately cost him his first career title.