(L-R) Usain Bolt of Jamaica, Su Bingtian of China, Christophe Lemaitre of France, Andre De Grasse of Canada, Julian Reus of Germany (back) and Trayvon Brommell of the US compete in the men's 100 metres semi-final at the 15th IAAF World Championships at the National Stadium in Beijing, China August 23, 2015. [Photo/Agencies]

Su had been using his right foot to start off in running for years. But he always found his third step a little bit weak and unsteady which would affect his intermediate running and the whole rhythm. After consulting with Yuan, Su changed to start with his left foot going forward first since last winter.

"It was like a desperate gamble, a brand new start for me. I knew if it works I would find some room to improve, otherwise it could lead to the end of my career," Su said.

"9.99s is like a landmark for China. As a Chinese I feel so proud to make such history. But I am not going to be over-satisfied with this result, I still have a long way to go and need to keep working hard in the future," said a modest Su.

Su's breakthrough performance is still no match of world best sprinters like Usain Bolt and Justin Gatlin, but Liu Hong, another flagbearer of Chinese athletics, has already signed her name on the world record book.

The 28-year-old race walker trimmed more than one minute off her previous personal best to win in one hour, 24 minutes, 38 seconds at the Spanish leg of the 2015 IAAF Race Walking Challenge in La Coruna, Spain in June, breaking the women's 20km race walk world record.

The former recognized world record was 1:25:02, set by Russia's Yelena Lashmanova when she won the Olympic gold medal in London 2012.

Her countrywomen Elmira Alembekova, Olimpiada Ivanova and Olga Kaniskina all registered a faster time with Alembekova's winning mark of 1:24:47 in Sochi in February being the fastest, but neither result has been recognized because the number of international judges at the event failed to meet the IAAF regulations.