Asia's number one golfer Hideki Matsuyama was forced to withdraw from the $8.5 million World Golf Championships-HSBC Champions in Shanghai with a bad back. The Japanese world number 28 had shot a solid one-under-par round of 71 on Thursday in the company of Spain's Sergio Garcia and Nick Watney of the US. But he awoke Friday with back spasms and informed tournament officials at Sheshan Golf Club 15 minutes before he was due to tee off in his second round that he would have no choice but to withdraw, losing his share of the $8.5 million prize pot. It means disappointment for the Japanese fans who have made the journey to Shanghai for the co-sanctioned US PGA, European and Asian Tour event. It has been a difficult October stretch for the 21-year-old  rising star, who has won three times this year in Japan. He also withdrew from the US PGA Tour's Shriners Hospital for Children Open in Las Vegas two weeks ago because of illness. Matsuyama made history to be the first Japanese amateur to play in the US Masters at Augusta in 2011, where he made the cut and won the silver medal as leading amateur. He made the cut again as an amateur in 2012. He turned professional in April this year and finished in the top 10 at both the US and British Opens in his rookie season and made his Presidents Cup debut against the US last month. In his first British Open at Muirfield this year, Matsuyama played the first two rounds in the company of world numbers one and two Tiger Woods and Adam Scott, eventually finishing in a tie for sixth place with Woods. Source: AFP