Carlos Alcaraz becomes the youngest-ever men's tennis World No. 1.

Carlos Alcaraz, who won the US Open title on September 11 at the age of 19, provided a preview of what appears to be a dazzling tennis career.

 The Spanish teenager won his first Grand Slam championship in New York by defeating Casper Ruud in four sets in the final, capping off an incredible run.

Carlos Alcaraz's victory in the US Open made him the youngest male tennis player to win a Grand Slam since Pete Sampras in 2005 and the youngest since Rafael Nadal in French Open.

Alcaraz enjoyed himself twice because he also rose to the top spot in men's singles tennis. In addition to competing for the US Open championship,

Alcaraz and Ruud also competed for the number one position after it was announced that Daniil Medvedev would resign from the position after failing to successfully defend

 his US Open title. The two young men in New York on Sunday had a lot on the line, but Alcaraz displayed maturity beyond his years to win glory.

Alcaraz made history by becoming the youngest World No. 1 in men's singles tennis during only in his second full season on the tour. No teenager had topped the ATP rankings

since they began (in August 1973). Prior to Alcaraz, Lleyton Hewitt, who was 20 years and 9 months old, held the title of youngest World No. 1 in 2001.

On Monday, September 12, when the ATP rankings are updated, Alcaraz will be formally ranked first.