Lionel Messi inspired Inter Miami to come back from 2-0 down to beat Cincinnati on penalties after their thrilling US Open Cup semi-final ended 3-3 after extra-time in Ohio.

Miami, who won the Leagues Cup on penalties against Nashville on Saturday, are now one win away from their second trophy since Messi joined the club last month.

The US Open Cup is American soccer's oldest and most important knockout competition, dating back more than a century to 1914 and is similar to England's FA Cup or Spain's Copa del Rey.

Miami will host the Houston Dynamo in the final on September 27 after the Texan side beat Real Salt Lake 3-1 after extra-time.

In the intense heat, with temperatures over 100 degrees fahrenheit (38 Celsius) at kick-off, Miami's unbeaten run since the signing of Messi and Spanish pair Sergio Busquets and Jordi Alba looked to be coming to an end.

Inter trailed 2-0 with 22 minutes remaining before the Argentine delivered two perfect assists to striker Leonardo Campana to take the game into 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 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 found the net to force extra-time.

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.