João Fonseca has definitively introduced himself to the world as the latest teen sensation in men’s tennis by upsetting No. 9 seed Andrey Rublev 7-6 (1), 6-3, 7-6 (5) in the first round of the Australian Open.

Fonseca has long looked like a star-in-waiting. Under pressure in his first Grand Slam set, he delivered beyond those lofty expectations

Fonseca will take on Lorenzo Sonego in round two, and Alcaraz - himself only 21 - sees the sky as the limit for the teenager