Su Bingtian of China successfully defended his 100m title in 10.31 seconds here at the 6th East Asian Games on Tuesday, as he realized his promise to perform better when competing with Japanese runners in the final.

"I will compete with strong Japanese rivals and you will see a better result in the final this evening," Su said after the semifinals in the morning where he ranked second in his group in 10.50 seconds.

Japanese sprinter Ryota Yamagata is Su's strongest opponent in this event. "Yamagata finished within 10.10 seconds twice in one day in the London Olympics last summer. And he is really a great challenge for me," Su said before the final.

Su lagged behind Yamagata for a long distance in tonight's final but made an overturn in the last 20 meters.

"I tried my best to run and gradually narrow the gap between us. Finally I won," Su said.

It was really a close duel for Su because Ryota Yamagata also clocked 10.31s with a slim disadvantage of milliseconds.

"This result is of course not my best, but after the 12th National Games last month I did not have time for systematic training. I felt that I could not gather my total energy this morning, however, my coach said that my status has been much better in the training this afternoon before the final," Su said.

Su could breathe a sigh as a defending champion and his gold also marked a successful ending for China in Tuesday's track and field events as six out of the 10 golds on stake went to the hosts.

China won men's shot put, women's 400m and 800m, men's triple jump, men's and women's 100m on Tuesday.

Japan won men's 5,000m, women's 10,000m as well as men's 800m, while South Korea got a gold medal in the men's 400m race.