First-half goals from Germán Berterame and Rodrigo De Paul secured the victory at Nu Stadium, with Messi providing the assist for De Paul's goal and playing a key role in the move that produced Miami's opener.
The result confirmed Inter Miami's place in the MLS post-season, extending their run of consecutive play-off appearances and strengthening their position near the top of the Eastern Conference standings.
Berterame breaks the deadlock
Inter Miami gradually grew into the contest after an evenly contested opening, with goalkeeper Matt Freese called upon to deny Sergio Reguilón's close-range header following a dangerous attacking move.
The hosts eventually took the lead in the 20th minute through a well-constructed team goal. Messi helped initiate the move before De Paul found Luis Suárez, whose low delivery across the goalmouth allowed Berterame to finish from close range.
The goal was an important moment for Berterame, who ended his scoring drought and registered his eighth goal of the regular MLS season.
New York City FC attempted to respond, but Miami remained organised defensively and continued to threaten whenever opportunities arose in transition.
Messi sets up De Paul before half-time
Miami doubled their advantage in the fifth minute of first-half stoppage time after launching a swift counter-attack.
Berterame carried the ball forward before finding Messi, who attracted the attention of several defenders and laid the ball into De Paul's path. The Argentine midfielder then unleashed a powerful right-footed strike beyond Freese to make it 2-0.
Messi's contribution once again underlined his influence on Miami's attacking play, as the forward helped create both goals that decided the encounter.
St Clair denies New York City FC penalty
New York City FC sought a route back into the contest after the interval, but Miami maintained their advantage through disciplined defending and important interventions from goalkeeper Dayne St. Clair.
Messi came close to adding a third goal, while De Paul forced Freese into an impressive late save that sent the ball against the woodwork.
The visitors were subsequently awarded a penalty deep into stoppage time after substitute Talles Magno was brought down by Ian Fray.
However, St. Clair produced a crucial save to deny Nicolás Fernández Mercau, preserving Miami's clean sheet and ensuring that the hosts finished the match with a two-goal advantage.
The shut-out was Inter Miami's second consecutive clean sheet, marking a notable improvement after a run of 10 matches without one.
Inter Miami secure play-off qualification
The victory confirmed Inter Miami's qualification for the 2026 MLS Cup play-offs, with the club continuing their defence of the title they won in the previous season.
The result also gave head coach Cristian González consecutive victories for the first time since taking charge, providing further encouragement as the regular season approaches its conclusion.
Miami remained second in the Eastern Conference standings following the win, keeping themselves well positioned for the post-season while continuing to pursue the best possible play-off seeding.
Goalscorers
• Inter Miami: Germán Berterame 20', Rodrigo De Paul 45+5'
• New York City FC: No goals
What next for Inter Miami and New York City FC?
Inter Miami are scheduled to travel to face Atlanta United on Saturday, 17 October, as they continue their preparations for the play-offs.
New York City FC, meanwhile, are set to return home to face Los Angeles FC on the same day, with the team looking to respond after another disappointing league result.
For Miami, Messi's creativity, De Paul's midfield contribution and St. Clair's decisive penalty save provided a strong foundation as the reigning champions continued their push for another MLS Cup title.