Carlos Alcaraz has become the youngest man to win a Grand Slam since Nadal in 2005|@carlosalcaraz|via Twitter

It was a Sunday Spaniard Carlos Alcaraz will never forget—it’s the day he clinched his first Grand Slam trophy and became the youngest ever world No. 1 tennis player.

The 19-year-old defeated Norwegian Casper Ruud 6-4, 2-6, 7-6(1), 6-3 to win the US Open at New York’s Arthur Ashe Stadium, becoming the youngest Grand Slam champion since countryman Rafael Nadal won, aged 19, at Roland Garros in 2005.

“It is something I have dreamt of since I was a kid. To be No. 1 in the world, to be champion of a Grand Slam, is something I have worked really, really hard [for],” Alcaraz said.

Alcaraz’s win came a day after Poland’s Iga Swiatek became a first-time winner at the US Open women’s singles, defeating Tunisia’s Ons Jabeur 6-2, 7-6(7/5).