7月21日，游泳世锦赛继续在光州进行，在男子400米自由泳决赛中，中国运动员孙杨以3分42秒44的成绩夺得金牌，豪取世锦赛400自四连冠，获得本届赛事个人首金的同时，也成为该项目历史第一人。这是孙杨个人世锦赛的第10枚金牌，追平罗切特并列第二位，仅次于菲尔普斯的15枚金牌。另一名中国选手季新杰获得第七名。

　　China's Sun Yang claimed gold in the men's 400-meter freestyle at the FINA World Championships in Gwangju, South Korea, with a time of 3:42.44. The gold medal is China's first in a swimming event at the meet. This is Sun's fourth straight title in this event and his 10th at the World Championships, which matched Ryan Lochte to rank No. 2 in history, only behind Michael Phelps who won 15 golds.