At first glance, it looks like Hyeon Chung’s future is so bright he’s got to wear shades even at 10 o’clock at night. Upon closer examination, they are prescription eyeglasses with sporty white frames that make him look a bit like a nerd – he is nicknamed The Professor after all – and a lot like a rock star out on the tennis courts.

The glasses are important for real and symbolic reasons. As a young kid, Chung took up the sport of tennis to help improve his eyesight. The 15,000 fans who watched him play in the fourth round of the Australian Open on Monday night may have damaged their own eyesight a little after the flashy combination of fierce groundstrokes and extraordinary defence that lit up Rod Laver Arena moments after an equally dazzling light and sound show had set the mood for the evening.

It was yet another much-anticipated match between a veteran champion and a young challenger. It was the six-time Australian Open champ Novak Djokovic – returning after a six-month layoff, and hoping for a comeback as spectacular as that of Roger Federer and Rafa Nadal a year ago – taking on the 21-year-old South Korean who had won the ATP Next Gen Finals in Milan last November.

That event has been modelled on the World Tour Finals but only for players 21 and under. In the final of that tournament, Chung had defeated Russian Andrey Rublev. In the third round of this year’s Australian Open, Chung beat yet another Next Gen star, Sasha Zverev, in a tightly-fought five-set match. But following that up with the best win of his career over a player of the caliber of Djokovic was going to be a tough ask.

Djokovic meets his match – literally

Before Monday night’s match, former world No 1 Jim Courier said on Australia’s Channel 7 network that Chung was “a very, very good imitation” of Djokovic. And in the post-match interview, the South Korean told Courier, “When I was young I just tried to copy Novak because he’s my idol.” It’s fair to say that the Serb literally met his match today.

The match began with Djokovic looking a little rusty. The crowd welcomed the former champion warmly and even seemed to be slightly in his favor. Certainly, they wanted to see him extend the match beyond three straight sets. The noise level in the stadium increased with every set, as it began to dawn on people that a massive upset might be brewing.

Djokovic has said that the elbow injury which took him out of the game after Wimbledon last year is still not 100% healed. He pulled out of the Qatar Open earlier this month, and has adopted a new, abbreviated service motion to help adjust after the injury.

But it was not a good serving day for Djokovic. He served four double faults in his first two service games, quickly going down 4-0. Over the course of three sets, he served nine double faults and only two aces. Moreover, he won just 65% of the points on his first serve and a pedestrian 39% on his second serve.

Still, when the 12-time Grand Slam champion fought back to take the first set to a tiebreak, it looked like he would use his experience here to prevail over the younger player. But Chung apparently had other ideas. Time and again the South Korean No 1 sent passing shots beyond a somewhat weary-looking Djokovic.

Though the fourteenth seed tried to pump himself and the crowd up from time to time with that characteristic roar of his, the night belonged to his young, bespectacled opponent. Even coach Andre Agassi’s encouragement as he stood up after nearly every point in Djokovic’s box, wasn’t enough to change the course of the match.

In the post-match interview, Djokovic acknowledged that his elbow has not healed. He told reporters, “I have to reassess everything with my team, medical team, coaches and everybody, scan it, see what the situation is like. Last couple weeks I played a lot of tennis. Let’s see what’s happening inside.”

Shining star

Despite Djokovic’s injury woes, however, Chung deserves a lot of credit for standing firm and not letting the pressure of the big occasion as well as his opponent’s resistance to thwart him. His reward: a first-ever Grand Slam quarter-final not only for him but also for South Korea. There he will face another first-time quarter-finalist, American Tennys Sandgren, who upset fifth seed Dominic Thiem. Chung will be a clear favourite going into that match.

In 2015, Chung was voted the ATP Tour’s Most Improved Player by his fellow players. Since then, other Next Gen players like Zverev and Shapovalov may have attracted more media attention. But right now, it’s the South Korean, who flies very much under the radar in his home country, whose star looks to be the most ascendant. Here in Melbourne, he’s enjoying quite a run.

Chung’s father, Seok-Jin, a former tennis player himself, seems to have had a refreshing attitude for a tennis dad. A few years ago, the then teenage Chung said this about his father: “He doesn’t want to give me any pressure. He just wants me to enjoy and play.”

On Monday night, Chung looked like he was doing exactly that. After the biggest win of his career, which caused an upset so huge that everyone was talking about it even on the following day at Melbourne Park, the strong and stocky Chung knelt to kiss the court. The fans at rod Laver Arena roared in appreciation for what he’d managed to achieve. It was one of those nights when it looked as if, with or without glasses, everyone could clearly see what the future of men’s tennis might look like.

As for South Koreans, they may just have to wake up to the fact that there’s a shining star representing them in world tennis. As Chung put it after his win, “In my country, I think tennis will be coming up after this tonight.”