By Shrivathsa Sridhar MELBOURNE (Reuters) -Endless queues outside Melbourne Park's 1573 Arena on a sunny Thursday afternoon gave casual fans the impression that a Grand Slam champion was in action, but a quick peek inside revealed the carnival atmosphere and explained the interest.

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