Inter Miami rallied from a 2-0 deficit to defeat Cincinnati on penalties after their dramatic US Open Cup semi-final ended 3-3 after extra time in Ohio.
Miami, which won the Leagues Cup on penalties against Nashville on Saturday, is now one win away from winning their second trophy since signing Messi last month.
The US Open Cup is the oldest and most prominent knockout competition in American soccer, stretching back more than a century to 1914, and is comparable to England’s FA Cup or Spain’s Copa del Rey.
After defeating Real Salt Lake 3-1 in extra time, Miami will host the Houston Dynamo in the final on September 27.
Cincinnati, which leads the Major League Soccer standings while Miami is last, would have been clear favorites a month ago. However, the Florida team is no longer the same one that was winless in 11 league games prior to the arrival of the Argentine.
Miami’s unbeaten record since acquiring Messi and Spanish trio Sergio Busquets and Jordi Alba appeared to be coming to an end in the extreme heat, with temperatures topping 100 degrees Fahrenheit (38 Celsius) at kickoff.
Inter trailed 2-0 with 22 minutes left until the Argentine supplied two flawless assists to striker Leonardo Campana to force extra time.
Messi’s compatriot Luciano Acosta had put Cincinnati ahead in the 18th minute and American striker Brandon Vazquez doubled the home side’s lead with a fine strike from the edge of the box in the 53rd minute.
In the 68th minute, Messi whipped in a free-kick from the left which was headed home by Campana to breathe some life into what had been a tired display from Gerardo Martino’s side.
Cincinnati thought that they had made it 3-1 but Yuga Kubo’s effort was ruled out for handball.
In the seventh minute of stoppage time Messi, from deep on the left, swung in a ball to Campana at the back post and again the Ecuadoran forward fopund the net to force extra-time.
Miami went ahead in the first period with Benjamin Cremaschi sliding an excellent pass into the path of Josef Martinez and the Venezuelan made no mistake with a precise finish.
But Cincinnati bounced back in the second period with Japanese winger Kubo firing a right-foot shot into the far corner past the diving Drake Callender.
The teams were at 4-4 in the shoot-out when Callender saved Nick Hagglund’s penalty for Cincinnati and Cremaschi converted the next to book Miami’s place in the final.
The 18-year-old Miami-born Cremaschi, whose parents are Argentine, was congratulated by Messi after his match-winning spot kick.
“I’m living a huge dream,” he told CBS Sports, “Sometimes I sit down and really think about the position that I’m in and it’s incredible, I never believed I was going to be in the spot I am in now,” he said.
There was a more sober view from Martino, whose team must now begin their 12 game attempt to climb from last in the Eastern Conference to the playoff positions.
Martino suggested he may be forced to rest some of his players, including Messi, after an intense eight-game spell.
“Both Leo and many other players are reaching an important physical limit and from today we will evaluate how we approach the next three matches,” he said.
“The fatigue is overcome with all the enthusiasm … I hope the team in the future could play better, but it’s very difficult to do that when you almost can’t rest”
Houston took the lead on the stroke of half-time through Mexican international Hector Herrera but Salt Lake levelled with a Julio Anderson goal in the 64th.
Panamanian midfielder Adalberto Carrasquilla fired in a fine solo goal in extra-time before Luis Caicedo wrapped up the win at the death.