Teenage tennis sensation João Fonseca frustrated his home fans at the Rio Open in a first-round loss two days after winning his first ATP title.

Teenager João Fonseca won his first ATP Tour title at the Argentina Open on Sunday, announcing himself as one of tennis’ brightest talents.

The home star Joao Fonseca failed to make an impression at the ATP 500 event in Rio. The 18-year-old competed in front of the home fans two days after lifting his first ATP trophy in Buenos Aires. The Brazilian failed to extend the winning streak following a 6-1, 7-6 loss to Alexandre Muller.

Rising tennis star João Fonseca has finished what he called “an unbelievable week” with a straight sets victory over Francisco Cerúndolo in the final of the Argentina Open to claim his first tour-level title.

Brazil's João Fonseca, 18, beat Francisco Cerúndolo in straight sets to win the Argentina Open for his first tour-level title.

Teenage tennis sensation João Fonseca frustrated his home fans at the Rio Open in a first-round loss two days after winning his first ATP title

Regardless of ranking and seedings, the story of this year’s Golden Swing is Joao Fonseca. He would have been the main narrative even if he was losing, but the Brazilian clinched his maiden ATP Tour title.