Joao Fonseca has left several remarkable data in his great triumph against Andrey Rublev in the first round of the 2025 Australian Open. The 18-year-old Brazilian has shown an average speed of his second serve 20 km/h higher than what the Top 10 has displayed so far in the first Grand Slam of the season, with his average being 175km/h, an absolutely spectacular figure considering his youth.