South Korean tennis player Chung Hyeon has defeated Novak Djokovic of Serbia and advanced to the quarterfinal of the Australian Open. 

Chung, placed 58th in the world rankings, crushed 14th-ranked Djokovic 3-0 in the season's first Grand Slam tournament on Monday at the Rod Laver Arena in Melbourne. 

In the round of 16, Chung knocked out the six-time Australian Open champion to win 7-6, (7-4), 7-5, 7-6, (7-3).

With the win, the 21-year-old has become the first South Korean to reach a grand slam quarterfinal. 

This was Chung’s second match with Djokovic. The two players previously met in the first round of the 2016 Australian Open, where Djokovic defeated Chung in three straight sets and went on to win his sixth Australian Open title.

Chung will now face 97th-ranked Tennys Sandgren of the U.S. on Wednesday, who also had an upset win against fifth-seeded Dominic Thiem of Austria.