© Mike Lawrence/ATP Tour

Rafael Nadal is pursuing his fifth US Open title.

Battle For World No. 1 At US Open Down To Nadal, Alcaraz & Ruud

Nadal in pole position to leave New York in the top spot

The battle for No. 1 in the Pepperstone ATP Rankings is down to three players following Daniil Medvedev’s fourth-round loss at the US Open on Sunday evening against Nick Kyrgios. Rafael Nadal is in pole position to leave New York in the top spot, while Carlos Alcaraz and Casper Ruud still have an opportunity to climb to the top of men's tennis' mountain

Alcaraz and Ruud must reach the final to have a chance to leave New York as World No. 1. If Nadal advances to the quarter-finals, he will force Alcaraz or Ruud to win the title.

Pepperstone ATP Live Rankings Round By Round

 Player  R4  QF  SF  F  Title
 Rafael Nadal  5,810  5,990  6,350  6,830  7,630
 Carlos Alcaraz  4,920  5,100  5,460  5,940  6,740
 Casper Ruud  -  5,010  5,370  5,850  6,650

Nadal is in the best position in the battle for No. 1, but Alcaraz also controls his own destiny because he is on the same half of the draw as the lefty and could eliminate him in the semi-finals. If Nadal reaches the final at Flushing Meadows, he will leave New York as World No. 1. If Alcaraz and Ruud play in the US Open final, the winner will leave New York as a first-time World No. 1.

If Alcaraz earns the top spot, he will become the youngest World No. 1 in the history of the Pepperstone ATP Rankings. If Ruud climbs to the pinnacle, he will become the first Norwegian to do so.

Ruud, who has already advanced to the quarter-finals, is up three spots to No. 4 in the Pepperstone ATP Live Rankings. Alcaraz is currently No. 5 in the live standings.

Entering the tournament, Medvedev and Stefanos Tsitsipas also had an opportunity to leave the season’s final major as World No. 1. It was not the first thing on Medvedev’s mind after his loss, but the 26-year-old is disappointed that he will relinquish the top spot.

“That's not nice because honestly after such a match, when you lose in Grand Slam, look, I'm trying to look good here, but I'm disappointed. Not going to cry in the room, but I'm a little bit disappointed,” Medvedev said. “For [a] few days I'm going to be just a little bit sad, looking at my phone, my laptop or watching some series. It was not the first thing on my mind walking after the match, saying, ‘Damn, will not be the World No. 1 any more.’ I actually don't know which place I will be…. But that's motivation [to] try to do better.”