GEOFF BENNETT: Three years after becoming the youngest number one player in history, Spain's Carlos Alcaraz has reclaimed the top spot, winning the U.S. Open in four sets over Italy's Jannik Sinner center and capturing his sixth Grand Slam title.

On the women's side, Belarus' Aryna Sabalenka defeated American Amanda Anisimova, becoming the first woman since Serena Williams to win back-to-back singles titles at the U.S. Open.

It's the second U.S. Open championship for both Alcaraz and Sabalenka.

For more on these historic victories, we're joined now by Patrick McEnroe, former singles and doubles champion and a longtime commentator on all things tennis.

It's great to see you.

So, Carlos Alcaraz did not lose a single set in the tournament until Sunday.

What impressed you most about his run and his performance yesterday?

PATRICK MCENROE, Former Professional Tennis Player: You know, I think it was his focus and his attitude.

Sometimes he can be a little up and down.

He's such a creative player.

He is a showman out there.

He loves to put on a good show for the fans.

But what most impressed me this year, Geoff, was that he seemed to be just dialed in right from the start.

Sometimes, you see him lose a set or two early in the tournament, when he just kind of loses a little bit of interest.

That didn't happen this year.

I think Jannik Sinner beating him at Wimbledon in the final there -- he had won it the last two years -- was a little bit of a wake-up call for Carlos.

So he seemed to be incredibly focused.

The serve was the best I have ever seen it in the championship match.

And he was absolutely hitting his forehand at just incredible speeds throughout the entire match.

And he set the tone early by going after Sinner.

Sinner was able to, I thought, overpower him a little bit in that Wimbledon final.

And Alcaraz came out with the mentality and the game plan on Sunday that he wasn't going to let that happen again.

And it was a really impressive and dominant performance from Carlos.

GEOFF BENNETT: Yes, it was an incredible championship match between Alcaraz and Sinner.

How do you see their rivalry shaping the sport moving forward?

PATRICK MCENROE: Well, it is incredible.

The last two years, they have split all eight Majors.

And it's been a long time since that's happened.

A guy by the name of Roger Federer and Rafael Nadal did that.

I think it was in 2006-2007.

So what they're doing is really separating themselves from the pack right now.

And it's going to be up to the other players.

Maybe it's Americans Ben Shelton, Taylor Fritz, Alexander Zverev.

Maybe there's a 15- or 16-year-old out there that's watching these guys and was going to say to himself, I got to start playing tennis like that.

I got to start taking huge risks.

I got to start being ultra-aggressive.

I got to have lightning speed.

Because, right now, they are clearly far and away the two best players in the world.

And I think there's no reason that that's not going to continue.

They both play great tennis on multiple surfaces, Sinner winning Wimbledon for the first time on grass.

Sinner was one point away three times this year in Paris of winning that title against Alcaraz in what was really one of the most epic matches I have ever seen, and Alcaraz able to come back and win that in five sets.

Sinner gets him back at Wimbledon, and now Alcaraz wins it here.

The next Major will be in January in Australia, and they will go in, the two of them, as heavy favorites again.

GEOFF BENNETT: And on the women's side, Aryna Sabalenka came in after a tough Wimbledon loss to the American and then beat her to defend her U.S. Open title.

What set out to you about her resilience and her path to victory?

PATRICK MCENROE: Well, not only did she come back from a tough Wimbledon loss.

She lost in the finals in Paris to Coco Gauff.

She lost in the final in Australia to Madison Keys, so two Americans.

She was the best player all year, consistently was the best player, but she really wanted to win that Major, which had eluded her.

She was going to keep the number one ranking no matter what, but I don't think it would have meant as much to her without the win in New York.

So you saw her emotions, her reaction after winning that.

Anisimova had another great tournament.

And, remember, she played the Wimbledon final, didn't win a game in that one, after beating Sabalenka in a great match in the semifinals.

So it was another great tournament for Amanda.

I think we're going to see her break through within the next year or two.

But certainly this stamps Sabalenka as clearly the number one player in the world for this year.

GEOFF BENNETT: And beyond the names we mentioned, who else caught your eye during this tournament and which storyline should we be paying attention to as the tour moves forward?

PATRICK MCENROE: Well, I think the players, a couple of players that I mentioned, the Americans.

Taylor Fritz had a good run, lost to Djokovic in the quarterfinals.

I think that's the match he could have won.

Ben Shelton unfortunately had to retire, got injured in that one.

And I think Amanda Anisimova has been an amazing story, to see her resilience, the way she came back after it really being embarrassed on the center court at Wimbledon and having such another good tournament.

The American women are very strong overall.

And I think the other thing to watch for is, how does Coco Gauff recover from what really was a difficult time for her with going through a new coach, kind of changing the mechanics of the serve, which is highly unusual to do that at any time for a professional, but particularly essentially right before and in the middle of a Major tournament.

So she's got a lot of work to do to sort of rebuild her confidence and find some sort of rhythm on that serve, because that really hurt her during this season, after winning her second Major of the year in Paris.

GEOFF BENNETT: Patrick McEnroe, great to speak with you.

Thanks for joining us.

PATRICK MCENROE: Thanks for having me.