Joao Fonseca definitively introduced himself to the world as the latest teen sensation in men’s tennis, upsetting No. 9 seed Andrey Rublev 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

Joao Fonseca has become the talk of the town in Melbourne after causing a big upset at the Australian Open. The 18-year-old qualifier stunned No. 9 seed Andrey Rublev in straight sets as he made his Grand Slam main draw debut on Tuesday.