Chung jumped seven spots to reach a career-high No. 49 in the Association of Tennis Professionals world rankings released on Monday.
|In this Associated Press file photo taken on Aug. 8, 2017, Chung Hyeon of South Korea hits a shot against Feliciano Lopez of Spain during the first round of the Rogers Cup tennis tournament in Montreal. (Yonhap)|
Chung's previous high had been No. 51 from October 2015.
Chung reached the third round at the Rogers Cup in Montreal last week.
Retired player Lee Hyung-taik owns the record for the highest-ranking position by a South Korean player at No. 36, attained in August 2007. (Yonhap)