NEW YORK (AFP) — Carlos Alcaraz insists he is "not afraid" as he targets the US Open title and a slice of history as the youngest men's world No. 1 on Sunday.

The 19-year-old Spaniard tackles Casper Ruud in a winner-takes-all final with both men chasing a maiden Slam crown and the top ranking.

"I'm not afraid of the moment," said Alcaraz, the youngest finalist at a Slam since compatriot Rafael Nadal won the French Open in 2005.

In a tournament which saw Novak Djokovic and Roger Federer fail to make the start, and four-time winner Nadal falling at the last-16 hurdle, Alcaraz has flourished in his status as champion-in-waiting.

His mesmerizing shot-making and flamboyance have seen him overcome three successive five-setters to make the final. He spent more than 13 hours on court in those three marathons.

Against Jannik Sinner, in a five-hour 15-minute quarterfinal which ended at 2:50 a.m. on Thursday morning, he saved a match point.

He then required four match points to finish off Frances Tiafoe in Friday's semifinal, which was the fourth longest match of the tournament.

It was Alcaraz's 50th win of 2022.

Such performances have convinced Alcaraz that the stars have aligned for him to capture his first Slam title.

"I've prepared myself mentally and physically to be fighting for the big things on Sunday," said Alcaraz, the youngest finalist in New York since Pete Sampras in 1990.

"I always dreamed of being No. 1."

Alcaraz has a 2-0 winning record over Ruud, who will be playing in his second Slam final after finishing runner-up to Nadal at the French Open in June.

One of those wins came on hard courts at the Miami final in March. It was one of Alcaraz's four titles in 2022.

In both previous meetings, Alcaraz has won in straight sets.

"I am just going for it and I'll enjoy the moment," said Alcaraz, whose coach Juan Carlos Ferrero ascended to the No. 1 spot when he made the 2003 final in New York.

Ruud, meanwhile, won't be afraid of slugging it out for five sets on Sunday — his four-hour 23-minute third round win over Tommy Paul was the tournament's third longest.

The 23-year-old will become No. 1 on Sunday if he becomes the first Norwegian man to win a Grand Slam title.

However, with eight of his nine career titles coming on clay, Ruud has been dismissed as a one-surface specialist.

His three titles in 2022, in Buenos Aires, Geneva and Gstaad, were all on clay.