Miami beat the Vancouver Whitecaps 3-1 on a historic night for the club, which was only founded by Beckham in 2018.
David Beckham shared an emotional embrace with Lionel Messi after Inter Miami's MLS Cup win
Miami won their first ever MLS Cup just six years after they were founded by Beckham
But the partners of Miami stars stole the show as Victoria Beckham joined in with celebrations
The Herons went 1-0 up inside the first eight minutes through a Edier Ocampo own goal before Vancouver levelled the scores in the second half thanks to Ali Ahmed's strike.
But Messi then turned on the style with a game-changing performance as he provided two assists to help Miami secure their cup triumph.
First he set up fellow Argentine Rodrigo de Paul for 2-1 in the 71st minute before teeing up Tadeo Allende's stoppage time goal to add gloss to the scoreline.
As Miami celebrated on the pitch after the game, Messi and Beckham were seen hugging and exchanging words as the Barcelona legend prepared to lift the trophy on stage.
However, the partners of Miami stars arguably stole the show on the day as Beckham's wife Victoria was seen enjoying the celebrations.
The former Spice Girls star looked glamorous as she joined Beckham in the directors box for the game wearing a grey suit jacket, with matching waistcoat and trousers.
They were also joined by children Cruz and Romeo as they posed with the MLS Cup trophy on the pitch after the game – though there was no sign of their other child Brooklyn.
Elsewhere, Inter Miami's contingent of former Barcelona players all celebrated their cup win with their partners too.
Messi and wife Antonella Rocuzzo enjoyed the trophy win together on the pitch
They were joined by ex- Barcelona stars Jordi Alba, Luis Suarez, Sergio Busquets and their partners Romarey Ventura, Sofia Balbi and Elena Galera
Messi shared an emotional moment with his wife Antonella Rocuzzo, who stunned in a gold crop top and jeans.
The high-profile couple posed for a photo with the trophy alongside Jordi Alba and his partner Romarey Ventura, Luis Suarez and wife Sofia Balbi and Sergio Busquets' wife Elena Galera.
Ventura was wearing a sleek black bodycon dress, while Balbi was seen in a cropped white top with baggy jeans.
Galera, meanwhile, was more minimalistic as she sported a black top and matching trousers.
It was an incredible moment for the club, who only started playing football in 2020.
Beckham hailed Messi's dedication to Inter Miami and his drive to win after breaking more records with the club – as he insisted he did not just join the club to enjoy the lifestyle in the city.
He said: "He's not just here to enjoy living in Miami. His wife and the kids love Miami, but he's come here to win, and that's really what Leo is all about.
"He wants to win. He's got that dedication, the loyalty that he shows to his teammates, to the city, to the club. Leo is a winner. It's simple as that."
On what the triumph meant to him, Beckham added: "I started this journey over 19 years ago and this was always my dream.
"My dream was to bring a club to this city and be successful – and also to bring in the best player in the world.
"This night as been pretty surreal and I'll cherish it forever. Tonight was the icing on the top of the cake and the cherry.
"It was meant to be for us today, our last game in the MLS in this stadium. What better way to go out."
Messi also enjoyed the moment with his family as children Thiago, Mateo and Ciro joined them on the pitch
