Former world No.1 Wang Xin guided China to a comprehensive 5-0 victory over Japan in a Group 1A tie of the 2011 Double Star BWF Sudirman Cup World Mixed Team Championships at the Qingdao Sports Centre Conson Stadium on Tuesday.

Wang Xin, who has dropped to No. 3 in the world behind compatriots Wang Shixian and Wang Yihan, was picked to play in the women's singles following Wang Shixian's much talked about defeat to Juliane Schenk on Sunday.

"I knew I had to win the point for my country and I'm lucky my coach (Li Yongbo) was on side lines giving me advice on how to play Sayaka Sato," said Wang Xin, who collected her first title of the year on May 1 when she won the YONEX SUNRISE Malaysia Open Grand Prix Gold.

"He told me to speed up my play as my opponent was not so quick. He certainly helped me today and my confidence is even better now."

Wang Xin was too hot for Sato to handle, winning 21-12, 21-11 to put China 2-0 up. Earlier, Cai Yun-Fu Haifeng defeated Shoji Sato-Naoki Kawamae 21-15, 21-14 in the men's doubles.

Lin Dan, was up next and the Olympic and Asian Games gold medallists had to work double overtime against a determined Sho Sasaki, who so nearly pulled off an upset. Lin Dan eventually prevailed 22-20, 21-19.

"I had the first game in my hand when I was leading 20-18 but didn't have the luck to finish him off as he reeled off four points in a row," said a disappointed Sasaki.

"Lin Dan was not at his best today, but he was still was too good. I'm closing the gap. I played (Lee) Chong Wei in Malaysia last month and it was another close loss (21-13, 21-14)."

Yu Yang-Wang Xiaoli made it 4-0 by beating Mami Naito-Shizuka Matsuo 21-15, 21-10 before Xu Chen-Ma Jin completed the rout with a 21-14, 21-10 victory over Hirokatsu Hashimoto-Mizuki Fuji.