Even prodigies must learn hard lessons in public sometimes. Carlos Alcaraz has won four major titles and extracts tennis wisdom at a disturbing rate, but there are plenty of situations on court that the 21-year-old has yet to confront. In Tuesday’s Australian Open quarterfinal against the 37-year-old Novak Djokovic, Alcaraz lost, 4-6, 6-4, 6-3, 6-4, and learned how to grapple with an opponent whose injury did not prevent him from playing at a world-historical level. 

At 4-4 in the first set, Djokovic slid hard while running to his right and seemed to tweak something in his left groin, causing him to grimace and stretch it out. On his next serve, he struggled to push off the ground with that leg. He lost the ensuing rally then shook his head at his player’s box, suggesting that he wasn’t right. Injury suddenly imperiled the most anticipated match of the men’s draw in Melbourne. After having his serve broken, Djokovic was evaluated by a physiotherapist, who took him off court to wrap up his left thigh. A doctor administered a dose of painkillers. Djokovic returned to the court and lost the first set to Alcaraz, who looked unfazed.

The second set offered a grim prognosis for the rest of the match. Djokovic, still compromised in his movement, began to hit the ball as hard as he could. He wouldn’t be doing that if he was confident in his legs. That level of aggression is not his typical strategy, which may well be the most sound strategy in the history of men’s tennis: a barrage of calibrated risks, upper-middle-pace shots aimed at relatively safe targets, shifting the trajectory of the rally whenever he wants to, until an unambiguous chance to kill presented itself. Instead he was a bit itchy, grasping at the earliest possible opportunity to end the point, rather than the best. But it was working—a reminder of what a viciously clean ball-striker Djokovic can be when he wants to be, how many different styles of tennis he can summon. He was also serving with great pace and accuracy, the skill which has kept him winning majors, even in his dotage.

On the other side of the court, Alcaraz appeared distracted. It’s a common and somewhat counterintuitive phenomenon in tennis: One player’s injury makes the other less secure in his gameplan. The uninjured player begins to overthink, to second-guess what had been effective up to that point. After the match, Alcaraz reflected on what went wrong here. “Honestly I felt like I was controlling the match—and I let him get into the match again. And that was the biggest mistake that I made today,” he said. “He showed that he had issues just moving a little bit in the second set, and I had to push him a bit more to the limit. And I didn’t do it. After that, he started to feel better.” 

Afterward Djokovic said that he noticed his opponent’s hesitation and tried to exploit it. “I saw it, and I try to use that to my advantage in a sense. To take the initiative of the rallies, and his hesitation. He was trying to play at some point quite a few drop shots and make me run,” he said. “I’ve been in the situations as well where the opponent struggles with injury but keeps going, and then you’re like, ‘The opponent is going for everything and he’s staying in the match,’ and then all of a sudden as the match progresses the opponent feels better. And then you’re starting to panic a bit with your game.”

Djokovic won the second set with that ultra-aggressive play. He was feeling better, the painkillers having done their work, and he began to play more like his usual self. In the third set, the tennis began to singe off eyebrows: an uncanny melding of offense and defense by two of the sport’s best-ever contortionists, on par with the best rallies produced by this intergenerational rivalry, like their Cincinnati final in 2023 or their Olympic gold medal match in 2024.

Djokovic said later that he was more or less unimpeded from the end of the second set through the middle of the fourth, and any observer could confirm that from his performance alone. This was some of the best tennis he’s played in the past five years. He was explosive off his feet and immaculate with his timing on the ball. He was careening side-to-side with that lateral movement. It was hard to imagine that this was the same player grimacing through an injury just a set ago. Perhaps Alcaraz was having trouble believing it, too. After losing the third set on an outrageous rally, the Spaniard seemed to adopt a fake limp, a gesture that the commentators interpreted as mockery of his opponent. After the match, though, Alcaraz was quite measured: “I’m not saying, like, he made a show. I’m just saying—I don’t know, it’s obvious and everybody saw it, that he’s struggling in the second set, and then the third and fourth set he showed he was really good.”

Djokovic re-upped his medication at the start of the fourth set and managed to close out the match, despite a late surge from Alcaraz. Djokovic said, sitting in press, that the drugs were wearing off and he was starting to feel the sensations of injury again. While he wouldn’t elaborate on the specific injury, he said it felt very similar to the hamstring issues he had at the Australian Open in 2023 en route to the title. But he would have two full days off to prepare for his next match, the 50th major semifinal of his career, extending his own record even further.

Going into this match, Alcaraz was 55-1 at the majors after winning the first set. This loss was an anomaly, and there are tactical reasons for that. In particular, it’s unreal how good Alcaraz is at tennis despite enduring imperfections with his serve, a foundational part of the sport. The disparity in second-serve was most glaring: Djokovic won 66 percent of points on his second serve, while Alcaraz won just 44 percent on his own, owing to their very different approaches. Djokovic hit hard second serves aimed out wide or right at the body that Alcaraz repeatedly misfired into the net, never really adjusting his return position. Meanwhile, Alcaraz’s own second-serve kickers were unthreatening enough that Djokovic swung freely at them for return winners.

But as is often the case in tennis at the highest level, the psychological takeaways might be even more constructive than the raw X’s and O’s. Djokovic, who has nothing left to learn on a tennis court, expressed some empathy for his young rival. “I feel for him. I understand that it’s not comfortable to play someone that you don’t know is he going to retire or not, is he moving, is he running, is he going to go, what’s happening? I felt he was looking at me more than he was looking at himself,” he said in press. If there is any hard criticism of Alcaraz at this juncture of his already impressive career, it’s that he can be distractible, prone to lose his peak level if something—like an opponent’s injury—rattles his focus. But if he manages to integrate the lesson of this match, that won’t be true for much longer.