NEW YORK — When Coco Gauff takes the court for her first U.S. Open final Saturday, her opponent will be the best player in the sport.

Or maybe it will be a ranting, raving, self-destructive head case. Or perhaps just a human being whose big, booming tennis often disguises her vulnerability and doubt. 

But for the first time in a tournament that has revolved around the 19-year-old Gauff in many ways, she will play a match that might not be about her at all.

Because, for better or worse, whenever she steps on the court, Aryna Sabalenka is always the main character.

"Every day is an entertaining adventure," said her fitness coach Jason Stacy.

How could it not be when you’re talking about a towering 6-foot Belarusian with a lion’s head tattoo on her forearm who screams and grunts and hits every ball like it wronged her, then disarms you immediately with her self-deprecating charm?

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You get all those elements from Sabalenka, who will take over the No. 1 spot in the women’s rankings regardless of Saturday’s outcome. You just don’t know how those quantities will be distributed in any given match, and which proportions will contribute to her brilliance or her self-destruction.

But after what she did Thursday night to beat Madison Keys in the semifinal, understand this: She’s going to fight, fight and fight some more for this U.S. Open title.

"I was just, like, come on, keep trying, keep pushing, like, I don't know, do something extra," Sabalenka said after finally finishing an epic 0-6, 7-6, 7-6 victory, during which she had to come from a break down in each of the final two sets. "I think this kind of thinking really helped me to stay in the game and to keep trying, keep pushing, to still have this belief that I have a chance to turn around this match."

Whereas Gauff is a towering figure in this match because of her age, her maturity and the desire to find a young female star who can fill tennis' Serena Williams void, Sabalenka is fascinating because we have seen a journey to the top of the sport that doesn't look like most of the others. 

The game’s great players are normally defined by how much they win on the biggest stages. Sabalenka is defined, in many ways, by how many times she has imploded and kept coming back. 

Before Thursday, Sabalenka had been to six Grand Slam semifinals. She had lost five of them, often in spectacular fashion. At Wimbledon in 2021, she lost from a set up. At the following U.S. Open, she wasted chance after chance and lost to Leylah Fernandez in three. And once again here last year, Sabalenka won the first set and was up 4-2 over Iga Swiatek in the third before letting it slip away.

In between, she went through a period of a few months months where she had the yips on her serve and was double-faulting 20 times in a match in some cases.

When tennis gives you that much scar tissue, it can easily be a ticket to oblivion. Instead, Sabalenka has become the most consistent version of herself over the past year, punctuated by an Australian Open title that she won over Elena Rybakina in a classic three-setter where she was the player who held her nerve the most. 

"It's like she puts more emphasis and pressure on a semi than a final," Stacy said. "She gets to a final and she’s like, OK, I’m here. Let's go. She wants to fight. She's like, 'This is mine. I'm going to take it from you, it's mine, go away,' kind of attitude when it's like in a final."

That’s why Thursday felt like such a significant moment in the sport. When Sabalenka lost the first set 6-0, the demons were lurking. Keys was playing well, but Sabalenka would have had every excuse to fall away mentally and eat another semifinal bust.

"I was all over the place. I was just, like, what can I do? Like, she's playing unbelievable, just, like, crushing everything," Sabalenka said. "I had zero control in the match. I was just, like, I was just keep telling myself, I mean, OK, there is going to be this like this? Somebody going to just play their best tennis? You just have to keep trying, keep staying there, and keep pushing it. Maybe you'll be able to turn around this game."

When Saturday’s final begins, it's possible Sabalenka will just bury Gauff under an avalanche of ball-striking power that few, if any, can match in the women’s game. Or it’s possible she’ll be unable to deal with the moment and start spraying errors without the ability to rein herself in. 

But Thursday's win was a statement that when you play Sabalanka, the last point is the one that matters most.