Later that year, Su qualified for the 2015 IAAF World Championships which were held in his home country of China. On 22 August 2015, Su raced in the first heat of the first round of the 100 metres finishing second behind Asafa Powell in 10.03 seconds. The following day, he was drawn in the first semi-final against defending champion Usain Bolt. Su finished in fourth clocking a time of 9.986 seconds tying Jimmy Vicaut's time in the third semi-final; since they were tied for the eighth-fastest time, they were both entered into the final, marking the first-ever nine-man final in World Championship history. Su then raced in the final, finishing 9th with a time of 10.06 seconds. Su subsequently became the first ever Asian-born athlete to run in a 100 m World Championship final.