Novak Djokovic has been a dominant force in men's tennis over the last one decade, and it is rare to see the Serb in tears after a loss - or suffer a loss at all. But both of those things happened at the 2016 Olympic Games, where the 17-time Grand Slam champion bowed out to Juan Martin del Potro in the first round and left the court sobbing.
What made the Argentine's 7-6(4), 7-6(2) victory even more remarkable was the fact that the two players were at opposite ends of the form spectrum at that time. Del Potro was returning to competitive tennis after his third wrist surgery, having contemplated retirement the previous season. Djokovic, on the other hand, was in possession of all the four Slams at the same time, after finally mastering the clay of Roland Garros.
Even though the Serb did suffer an early defeat at Wimbledon, that was considered by most to be a natural consequence of burnout. With the Olympic gold being one of his biggest goals of the year, it was widely expected that Novak Djokovic would regroup and run all the way to the title in Rio.
As the top seed, the World No. 1 was the unanimous favorite to overwhelm the returning-from-injury Del Potro. But what unfolded on the Centre Court of the Olympic Tennis Center that day left the tennis world shell-shocked.
A frustrated Djokovic had no answer to the towering Argentine's fearsome forehand in the two tie-breaks they played. A highly motivated Del Potro unleashed winner after winner past a dazed Djokovic, ultimately pulling off the incredible upset.
That match also marked the beginning of the Serb's problems with his right elbow, which would eventually compel him to take a long break in 2017.
Novak Djokovic felt he had disappointed his country: Djokovic's mother
The defeat to Del Potro really stung Novak Djokovic, and according to his mother Dijana, it was the most painful loss of his career.
Dijana recently admitted in an Instagram live session, as reported by Informesinbandera.com, that she has never seen her son cry as much as he did that day.
"That defeat still breaks my heart," Dijana said. "The tears I saw on that occasion are the greatest I have ever seen. He had everything to win gold but the wish was not granted. He had that problem in his elbow and he could not endure the pressure. He felt he had disappointed the people of Serbia."
While the eight-time Australian Open winner has tasted glory at each of the four Majors, the Olympic gold continues to elude him. He had made it his mission to bring home a glittering medal for Serbia from Rio, and his inability to do so hurt him badly.
Djokovic has talked about the way he felt that day in many subsequent interviews. Speaking to Globo Esporte in 2018, he revealed that he had a deep connection with his Brazilian fans who had come out in hordes to support him - which made it tough to stomach that he had let them down.
Djokovic also said he was playing the best tennis of his life at that point of time, and had genuinely believed it was his best chance to capture the gold. Victory in Rio would have capped what was an absolutely immense phase of his career, but it was not to be.
Being so close to winning it all, and then having the biggest prize taken away at the last minute, made the loss more devastating than any he had ever experienced.
"I think that God brings this kind of experience because we need to learn, understand, grow. And accepting it as most as possible," Djokovic had said. "And I accepted, I went forward, I knew it had to happen and I suffered about it for a long time because it was the most important time in my career and I wanted to fight for the medal in Rio. It would have been perfect."