The 21-year-old had a huge breakthrough in January at the Australian Open, where he defeated former No. 1 Novak Djokovic, among others, to reach the final four. Chung retired from his semifinals match against the eventual champion Roger Federer with blisters on his foot but still jumped from No. 58 to No. 29 in the world rankings. Former ATP player Lee Hyung-taik had been the top-ranked South Korean at No. 36 since 2007.

Chung sat out a couple of weeks after the Australian Open to treat blisters and slipped to No. 30 on Feb. 12. And Chung reached the quarterfinals at the first two tournaments since his return, including last week's Mexican Open and set a new career high in his ranking position.

Chung is the second highest-ranked Asian on the tour behind Kei Nishikori of Japan, who went up a notch to No. 25 this week. (Yonhap)