Javelin thrower Lyu Huihui is on her way to a silver medal, which she won with a throw of 66.13m.WEI XIAOHAO/CHINA DAILY
The home quartet delighted a rapturous crowd to clinch Asia's first silver in the sprint relay at the "worlds".
Su also became the first Asian athlete to reach the 100-meter final after equaling his national record of 9.99 seconds in the semifinals.
Long jumper Wang Jianan, 19, leapt more than 8.18 meters to clinch Asia's first bronze medal in the event.
The progress achieved by a new wave of Chinese athletes in Western-dominated events has made up for Liu's retirement. The hurdler became a national hero after winning the 110-meter gold at the 2004 Athens Olympics.
Liu, who worked as a guest TV commentator during the championships, was emotional as the men's relay team waved the national flag, an honor that was supposed to be his seven years ago.
"I am truly overwhelmed by this history-making moment, and I can't express how happy I am for them," the 32-year-old said.
China's solid improvement in athletics also attracted the attention of Sebastian Coe, the new president of the IAAF.
"It's very obvious that China will play a huge part in the development of our sport going forward," the Briton said on Sunday. Coe said he could see there was a desire for Chinese athletes not to sit back on Liu's past success.
"They were very keen to establish some expertise in many other disciplines in track and field. The relay silver is pretty indicative of the progress that Chinese athletes have made," he said.
