The 54th-ranked Chung made it two wins out of two in the round robin format being used in the inaugural edition of the under-21 version of the ATP Tour finals.
Chung beat Russia's Andrey Rublev 4-0, 4-1, 4-3 (7/1) in their Group A match a day after rallying from a set down to get past Canadian Denis Shapovalov.
"The score looks easy, but it was not easy on the court. Every point was a fight," said 21-year-old Chung who is guaranteed of finishing top of the group.
Coric was up two sets to one and 3-2, 40/15 and serving for the match, but thanks to the no-advantage scoring system, when he reached deuce, everything was on the line.
One more point and he could force a tie-break, and from there a fifth set, but Medvedev could not save a third match point.
"I think it was really physical," Coric said. "The first two sets were extremely tough."
Jared Donaldson is out of the running after a second loss, falling to Khachanov 4-1, 4-3 (7/3), 4-2.
Pre-tournament favourite Rublev, ranked 37th and winner of his first title in Umag this year, had won his opener against Italian wildcard Gianluigi Quinzi.
In the second Group A match, Shapovalov beat Quinzi 4-1, 4-1, 3-4 (5/7), 4-3 (7/5).
Rublev can still make the semi-finals on Thursday when he plays Shapovalov but former Wimbledon junior champion Quinzi is out of the running.
Disclaimer: No Business Standard Journalist was involved in creation of this content
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
