Still, the Italian was mightily impressive in seeing off championship leader Oscar Piastri by 0.045sec at a sunlit Hard Rock Stadium, home of the Miami Dolphins.
Piastri’s team-mate Lando Norris was third best, exactly a tenth behind Antonelli.
World champion Max Verstappen, a new father to his first child Lily, was fourth quickest and George Russell in the other Mercedes fifth best, three-tenths short.