João Fonseca delivered a solid punch in the first round, knocking out ninth-seeded Russian Andrej Rubljov.
But in the second round, it came to an end for the former junior world number one, who qualified for the Australian Open and made his Grand Slam debut in Melbourne.
Fonseca had strong support from the audience, but ultimately had to give up in a tough five-setter that lasted over three and a half hours.
Sonego won with 6–7, 6–3, 6–1, 3–6, 6–3. Fonseca had a break ball in Sonego's serve at 3–3 in the deciding set, but when that chance went awry, the match swung in favor of the Italian with a serve break in the next game.
Despite the loss, the fans chanted "Fonseca" afterwards, a name that the tennis audience will likely see much more of in the future.
Holger Rune is also advancing to the third round. The 13th-seeded Dane won against Matteo Berrettini, Italy, with 3–1 in sets.
