Birmingham, England:The All England Championships became an All China event in an all but name on Friday. World champion Lin Dan led the way as China filled the men's singles semifinals, and three Chinese players advanced to the women's final four along with Chinese-born French player Pi Hongyan. Lin needed all of his skill and patience to grind out a quarterfinals victory over Sony Dwi Kuncoro in 64 minutes, the longest match of the men's singles so far. The left-hander, bidding for his third All England title and fourth consecutive final appearance, beat the Indonesian 18-21, 21-11, 21-18. He was also taken the distance by qualifier Simon Santoso of Indonesia in the first round. "I should concentrate more," Lin said. "I am taking the lead in games but then I am letting my opponent back in by not finishing the game off. "I am in relatively good form but there are still some dangerous opponents out there. I am hopeful of being in the final on Sunday." Lin meets Bao Chunlai in a repeat of their world final at Madrid in September. Fifth-seeded Bao needed three sets to overcome qualifier Shoji Sato of Japan 21-10, 8-21, 21-12. In the bottom half of the draw the last European hope exited as second-seeded Chen Jin beat seventh-seeded Kenneth Jonassen of Denmark 21-19, 21-19 in 44 minutes, while in an equally close contest, sixth-seeded Chen Yu put out Commonwealth champion and third seed Lee Chong Wei of Malaysia 21-19, 22-20. In women's singles, a third consecutive final showdown between Xie Xingfang and Zhang Ning was still on the cards. Holder and top seed Xie beat teammate Jiang Yanjiao 21-8, 21-17, and lined up another Chinese in fifth-seed Zhu Lin after she ended the hopes of Germany's Xu Huaiwen 19-21, 21-19, 21-17 in the longest match of the women's event at 70 minutes. Only France's Pi can stop the Chinese charge after she put out third seed and former Chinese player Wang Chen of Hong Kong 19-21, 21-18, 21-11. Second-seed Zhang, the Olympic champion who has never won the All England, knocked out Malaysian Wong Mew Choo 21-17, 21-15. China's strength was such that it was still on course for the first ever clean sweep of the titles, with world champions Cai Yun and Fu Haifeng through to the last four of the men's doubles. Gao Ling and Huang Sui are chasing their seventh consecutive title in the women's doubles but China also has two other pairs through to the last four. Gao is also bidding to retain her mixed doubles title with new partner Zheng Bo, a chance they enhanced after beating world champions Nathan Robertson and Gail Emms of England 21-17, 18-21, 23-21 in 78 minutes in the longest match of the tournament. But, as in the women's doubles, China has three pairs through to the mixed semifinals.