Four nights after scoring in his final match for the Albiceleste in a victory over Benin, the 39-year-old South American superstar struck in the 47th and 60th minutes as defending MLS champion Miami won for only the second time in their past 11 league matches.
A first-half brace by Luis Suarez staked the Herons to the lead as they improved to 13-5 with 10 drawn for 49 points, jumping from third to second in the Eastern Conference.
Uruguayan striker Suarez scored in the third minute to give Miami the lead, blasting a left-footed shot from the heart of the box into the top left corner.
Suarez struck again in the 39th for his 16th goal of the campaign, assisted like his first of the night by German Berterame.
Messi blasted home a left-footed shot off an assist from Suarez to give Miami a 3-0 lead and evaded three defenders to add another goal 13 minutes later as the pink-clad hosts pulled away to stay.
This was arguably the most dominant Miami have looked in quite some time, as they've not won an MLS regular season contest since August 29th, with four draws and a loss since that point. However, on Saturday, their biggest stars stepped up, and with hopes of going back-to-back, the team may have found some momentum with just six games remaining in the season.
Messi hopes to make Miami the first team to win back-to-back MLS titles since the Los Angeles Galaxy in 2011-12. Messi, the top point producer in the league with 23 goals plus assists on 13 others, seeks a third consecutive MLS Most Valuable Player award.