An inspired Hyeon Chung ousted 6-time Australian Open champion Novak Djokovic in the 4th round Monday night.

In a stunning display of speed, flexibility, stamina, and shot-making, 58th-ranked South Korean Hyeon Chung ousted 6-time Australian Open champion Novak Djokovic in their 4th round match Monday night 7-6 (4), 7-5, 7-6 (3).

The back-and-forth match included topsy-turvy tennis from both players with Chung racing out to the lead in all three sets but Djokovic clawing back to even each time.

Chung won the first four games in decisive fashion, but the Serb, whose ranking has dipped down to 14th in the world after a lengthy absence due to an elbow injury, fought back to eventually lead 6-5.

Heading into the first set tiebreak, Djokovic looked to be the stronger player. The 12-time major winner fired a strong forehand winner on the opening point and later erased Chung’s minibreak advantage and reached 3-all after a long rally that ended in a lunging volley winner. Undaunted, the Korean used strong forehands to re-take the lead and earn three set points. Djokovic fired a return winner on the first, but sent a weak forehand slice wide on the second.

Chung produced an inspired display of shot-making, speed, and flexibility the likes of which Djokovic himself would be proud of.

The Serb was seen shaking out his arm on multiple occasions and had treatment on his elbow after the first set.

Djokovic had a handful of opportunities to earn an early break in the opening game of the second set, but the man heralded by some as the greatest returner in the history of the sport was unable to capitalize and Chung eventually held with a running forehand winner down the line.

In the next game, it was the Korean who seized the advantage after once again out-hitting his opponent from the baseline in a series of rallies and eventually claiming the break with a stinging backhand pass winner.

Chung eventually led 4-1 after an easy service game in which Djokovic seemed to audibly grunt in pain when lunging for a ball. The Serb’s demeanor was reserved and even docile throughout most of the match. But he re-gained some traction in the match as Chung’s level dipped. Djokovic broke back after a Chung forehand miss and the pair would then trade holds up until the Serb served at 5-6.

Djokovic struggled with an elbow injury that kept him out for much of last year and did not appear mentally engaged for large portions of the match.

Djokovic had chances to hold and send the set into a tiebreak, but Chung raised his level and the Serb blinked with enough mistakes that eventually the Korean held a set point. Djokovic fired away from the baseline relentlessly, but Chung’s defense held firm until the Serb eventually misfired again.

To open the third, Djokovic did earn the break of serve that he had been unable to in the second, but Chung fired right back eventually would go on to reel off three straight games and lead 3-1.

But Djokovic came right back as well. Serving at 3-1, Chung saved one break point with more powerful hitting, but the Serb kept the game going behind some outstanding shot-making, including a lunging volley and a forehand return winner up the line. He eventually broke back after Chung hit long.

From that point, the players traded relatively uneventful holds. With Chung serving at 4-all, Djokovic finally showed some life. After running down a dropshot and producing an acute backhand winner to get to love-30, the Serb looked to the crowd and waved his arms with excitement. But Chung stabilized, getting back to 30-all and then firing a forehand winner after a long rally en route to an eventual hold.

Another trio of service holds ensued, setting up another tiebreaker.

Chung earned the first minibreak with a forehand winner, but Djokovic again battled back to get back on serve after a long rally that ended with Chung missing a desperation forehand. The Korean finally put the nail in the coffin by earning a 5-3 lead with the point of the match. Djokovic once again seemed in control of the rally, but Chung used his movement and flexibility to reach a difficult ball and hook a forehand pass winner.

One point later, the Korean earned three match points. Djokovic missed a backhand on the first.

After the match, the Korean praised Djokovic for helping to shape his game.

“When I’m young, I’m just trying to copy Novak because he’s my idol,” Chung said.

Chung will advance to the quarterfinals Wednesday to face American Tennys Sandgren, who defeated 5 th-seed Dominic Thiem in five sets.