Joao Fonseca defeated Ugo Humbert 6–4, 6–3 in the first round of the Miami Masters, a hard-court ATP Masters 1000 event, on 22 March 2025. The result constituted an upset, as Humbert entered as the pre-match favourite at 1.69 odds to Fonseca's 2.27. Fonseca's composed performance across both sets, particularly his control in the second, proved decisive in dismantling the French player's challenge. The Brazilian's clinical execution and consistency in holding serve allowed him to dictate rallies and convert break opportunities when they arose. This victory signals Fonseca's growing confidence on the hard courts and suggests momentum heading into the second round.