Chinese sprinters Su Bingtian and Xie Zhenye are locked in a fierce but friendly rivalry that is propelling them ever faster -- just in time for the Asian Games.
The speedsters have been in ominous form in recent weeks, bringing out the best in each other ahead of the Games in Indonesia, starting on Saturday.
Xie snatched Su's unofficial title of China's fastest man in June when the 24-year-old ran 9.97sec in France.
Then, just three days later in Madrid, the 28-year-old Su struck back with his lightning 9.91sec to add another chapter to their rivalry.
More significantly, it matched the Asian record set by Femi Ogunode of Qatar three years ago, and made Su the fifth-fastest man in the world this year over 100m.
Randy Huntington, Su's American coach, believes the sprinter can go faster still, saying he has the potential to go under 9.80sec.
Su, the world indoor silver medallist who also won silver at the last Asian Games, behind the Nigerian-born Ogunode, countered: "So now I have a new goal."
Xie, who remains in the better-known Su's shadow, tweaked his ankle last month but is expected to be fully fit for the Asian Games, which will be held in Jakarta and Palembang.
While Su has the edge in the 100m, Xie is the man for the 200m, setting a new Chinese record in May in Japan of 20.16sec.
"We have a very good relationship," Xie told SPIKES, the website and magazine of athletics' world governing body, the IAAF.
"We all send our best wishes to each other when we compete and even though we are also opponents, I believe that this relationship as adversaries can help us both go faster."
Adding to the feeling that Chinese sprinting has never had it so good is the form of Wei Yongli, 26, the reigning Asian Games champion who broke the 11-second barrier last month with 10.99sec in the 100m.
"Our progress lets more people know that we Chinese can do it in sprinting and lets many athletes in China feel confident and get strength," said Su, who recently became a father.
- Youthful squad -
China are taking the Asian Games seriously -- regional pride is at stake, and they will again expect to top the medals table -- but they are clear that the 2020 Tokyo Olympics are the ultimate aim.
"This Asian Games functions as a mid-term test and a valuable experience leading up to Tokyo 2020," Liu Guoyong, a senior official at the State General Administration of Sport, told the Xinhua news agency.
"It also serves as a comprehensive check on the state of competitive sports in China."
China will have a bulging squad of 845 competitors and take part in every event in Indonesia except weightlifting and kabaddi.
China, along with eight other countries worldwide, are banned from international weightlifting because of multiple doping violations.
Other stars who will feature for China at the Games include Sun Yang, the controversial three-time Olympic swimming champion, ageing badminton legend Lin Dan, and Zhu Ting, the star women's volleyball player.
With an eye on Tokyo and beyond, Chinese sports officials are stressing the youthful nature of the Chinese squad for the Asian Games.
About three-quarters of the country's competitors have never been to an Olympics or Asian Games before, according to state media.
"The Chinese delegation is aiming to demonstrate both sportsmanship and sports prowess at the Asian Games, which will also help us find promising stars and allow our young athletes to gain practical experience," Liu said.