World number eight and defending US Open champion Marin Cilic was made to work for victory against South Korean teenager Chung Hyeon in the second round of the Washington Open on Wednesday.
“It wasn't easy to put him away. He's a great counterpuncher,” Cilic told AFP about his young opponent.
Hyeon broke Cilic in the seventh game of the first set to establish a 4-3 lead, but the scores were leveled after he dropped his serve in the next game.
The world number 77 managed to force the set to a tiebreak, but Cilic’s experience told and he eventually triumphed 7-6 (7-2)
Hyeon was unable to continue his impressive play in the second set and slipped to a 4-1 deficit after dropping his serve in the first and fifth games.
The 19-year-old managed to break back in the sixth game, but Cilic sealed victory and his passage to the third round when he broke Hyeon in the ninth game for a 6-3 win.
The game was Cilic’s first on hardcourt this year, and his first since losing to Novak Djokovic in the quarter-finals of Wimbledon in early July.
Up next for the Croatian is American Sam Querrey, who defeated Japan's Go Soeda 6-3, 5-7, 6-4 on Tuesday.