Since Lionel Messi joined the MLS team last month, Inter Miami has come back from a 2-0 deficit to reach two finals.
In a nail-biting US Open Cup semifinal at FC Cincinnati that ended 3-3 after extra time, the 36-year-old Argentine attacker had two assists.
On Saturday, Miami defeated Nashville in a shootout to claim the Leagues Cup.
Since the club was founded as an expansion team in 2020, that was its first significant honor.
They will now make their debut in the US Open Cup final, the country’s oldest and most prestigious football knockout tournament, which dates back to 1913.
When the MLS season was suspended in July for the Leagues Cup, Miami was at the bottom of the standings while Cincinnati was at the top.
However, since adding Lionel Messi and his former Barcelona teammates Sergio Busquets and Jordi Alba, Miami has gone winless in eight games.
Luciano Acosta and Brandon Vazquez had given Cincinnati a 2-0 lead with 22 minutes left when Messi crossed the ball twice, setting up Ecuadorian striker Leonardo Campana for a goal with a header in stoppage time.
Following a ball from Benjamin Cremaschi that gave Gerardo Martino’s Miami team the lead early in extra time, Yuya Kubo tied the score at 3-3 after 114 minutes.
When the shootout was tied at 4-4, Miami’s Drake Callender made a stop on Nick Hagglund’s penalty shot before Miami-born Cremaschi, 18, made the game-winning penalty kick.