Carlos Alcaraz, 19, becomes youngest world No. 1 in men's ATP rankings history after US Open title | CBS Sports Headlines Carlos Alcaraz, 19, becomes youngest world No. 1 in men's ATP rankings history after US Open title Alcaraz defeated Casper Ruud on Sunday in New York for his first … Continue reading Carlos Alcaraz, 19, becomes youngest world No. 1 in men's ATP rankings history after US Open title