Novak Djokovic reacts after he wins a game against Tallon...

Novak Djokovic reacts after he wins a game against Tallon Griekspoor during the second round of the U.S. Open at the USTA Billie Jean King National Tennis Center on Thursday. Credit: Kathleen Malone-Van Dyke

When it comes to fan etiquette, tennis is not like most other sports.

Spectators are supposed to act more like they are at the theater than a sporting event with 10,000 plus people. Fans are expected to refrain from leaving their seats until players change sides of the court. During the point, they are supposed to keep quiet, which means no cheering, chatting or talking on your phone. Fans are allowed to cheer — and, yes, in some cases they actually boo — but only after a point is completed.

Suffice to say, there are no Fireman Eds at the U.S. Open. A tennis equivalent of "Trae Young sucks" would never break out at Arthur Ashe Stadium. No matter how many Grey Goose cocktails you have, there’s no way you could get your fellow spectators to join you in doing the wave.

Put into this cultural context, it’s easy to see why Novak Djokovic was so upset with a spectator who apparently didn’t get the fan etiquette memo before attending Djokovic’s 6-2, 6-3, 6-2 second-round win over Tallon Griekspoor on Thursday.

The unnamed fan in the first row seemed intent on throwing Djokovic off. He shouted right before the Serb attempted (and missed) an overhead smash. After he continued to shout at key points, Djokovic gave the fan a death stare during a change over and then went on to complain to the umpire.

Despite having little trouble winning the match, Djokovic explained afterward why he was so upset, adding that he was "not a spoiled brat."

"When tennis players talk about that, someone who is watching a team sport would say ‘What a spoiled brat.’

"But it’s a different sport. Look, there’s a lot of noise happening in the stadium, particularly in the night sessions. I don’t mind that. Even sometimes during the point it happens that people out of excitement, they just scream or they release like a sound or whatever, sigh, whatever you call it. And that’s fine.

"But if someone intentionally does it over and over again, then I have tolerance up to a certain point, then it’s not correct, then it’s not fine. It’s not fair. I feel like it’s not good for us players. I mean, particularly that guy for some reason was calling, raising the sound and kind of screaming just before I would hit my smash, which was a big point."

"I think, you know, that wasn’t nice. That’s all. I don’t mind the noise. Don’t get me wrong. I think it’s important for the entertainment, for the crowds, the music. I get it. But if someone does it over and over again, particularly when you are at his side, he knows why he’s doing it. The guy that I pointed out, he knew exactly what he was doing, and that’s all."

Djokovic, the No. 1 player in the world, is trying to complete a rare calendar grand slam by winning this tournament. Only five players have done it previously, and no one has done it since Steffi Graf in 1988.

He is also trying to win his 21st major championship, eclipsing the mark he shares with Roger Federer and Rafael Nadal. Djokovic is 2-0 at Flushing Meadows this week and 23-0 in Grand Slam tournaments this year, with five more wins standing between him and history.

For all of his wins, however, Djokovic never has won over the hearts of most tennis fans. When it comes to public affection, he is widely considered the third wheel of the Federer-Nadal-Djokovic era.

"I am motivated as ever to do well," Djokovic said. "I am trying to be the best I can be every single day and let’s see what happens."

The best he can be, without being heckled. Whether or not fans like Djokovic, he deserves the same bizarre courtesy that the rest of the players in his sport receive.