Yuki Koike clocked 9.98 seconds in the men's 100-meter race at the Muller Anniversary Games on Saturday to become the third Japanese sprinter to break the 10-second wall.
Koike shaved 0.6 second off his personal best to place fourth at the 10th event of the IAAF Diamond League season, won by South Africa's Akani Simbine with a time of 9.93. Former Japan record holder Yoshihide Kiryu finished seventh with 10.13.
"It was nearly a perfect run under the circumstances," said Koike, who matched Kiryu's 2017 record time with the help of a 0.5-meter tailwind.
"I was really nervous. If you don't feel that tension, your body won't move. I put pressure on myself by thinking that if I didn't put out (a good result) here, I wouldn't be able to compete in the world championships."
The 24-year-old, who is ranked 11th in the world and second in Japan in the 100, said with the right training and mindset he may be able to notch an even faster time.
"I think I can run it a little faster, but I don't know. In my current shape, I think I'm running close to my best. If I return to Japan and train, and drill with techniques that match my body, I think I can grow into another person," Koike said.
"I'm looking forward to the future. I think I'll be able to run better than I did today once again."
Japan's Abdul Hakim Sani Brown holds the national 100 record of 9.97 seconds, set in June at the NCAA Division I outdoor athletics championships.
Koike and Kiryu will take part in the men's 4x100 relay on Sunday in London. Koike will appear in the men's 200, a distance in which he claimed gold at last year's Asian Games in Indonesia and silver at April's Asian Championships in Doha, Qatar.
The 2019 IAAF world athletics championships kick off in late September in Doha.