Spanish 18-year-old Carlos Alcaraz beat Argentina's Diego Schwartzman in two dazzling sets Sunday to win the Rio Open final, becoming the youngest ATP 500 champion ever.

Looking faster, stronger and fitter than his 29-year-old opponent, Alcaraz put on a clay-court master class in Rio de Janeiro, winning 6-4, 6-2 in a match likely to bolster his reputation as the "New Nadal" -- a nickname he dislikes.

"I can't believe it, it's a great feeling. Despite all the difficulties, it's been a spectacular tournament," Alcaraz said after claiming the second title of his career, following Umag in July -- also on clay.

The win will take Alcaraz, who went into the match ranked 29th in the world, to 19th in the ATP's next rankings Monday.

Alcaraz broke Schwartzman's serve twice in the first set, the second time with the score tied at four games apiece.

He started the second set with another break, and continued to dominate from there.

Alcaraz reached the final beating world number 38 Fabio Fognini in the quarter-finals and world number six Matteo Berrettini in the semis -- both played Saturday due to rain delays.

Schwartzman, who was playing the 14th final of his career, looked more tired after Saturday's double header, which for him ran to a total five and a half hours on court.

In Monday's new rankings, he is expected to move up one spot to 13.