The eight-time Ballon d’Or winner hadn’t played since injuring his right ankle during the Copa America final on July 14, when he helped Argentina to victory over Colombia.
Since then he had missed eight MLS games for his club and this month’s World Cup qualifiers for his country.
Messi hadn’t played for Inter since June 1, but he didn’t miss a beat as he was inserted into the starting lineup.
“The truth is that I’m a little tired,” he said after the match. “The heat and humidity in Miami don’t help much either, but I really wanted to come back, I had been off of the field for a long time.
“Little by little I was training with the group, feeling good and that’s why we decided that I would start, and I’m very happy — very happy.”
Miami coach Gerardo Martino was delighted to see his star come out “feeling good” after 90 minutes.
Philadelphia seized the advantage in the second minute on Mikael Uhre’s left-footed shot from outside the area.
Messi grabbed the equalizer in the 26th minute, collecting a pass from Luis Suarez and beating defender Kai Wagner before unleashing a right-footed shot to cap a sequence launched by Jordi Alba on the left.
Ecstatic fans were still celebrating when he fired Inter ahead in the 30th, connecting again with Alba and firing a left-footed shot from the center of the area into the bottom right corner.
Inter thought Suarez had made it 3-1 before halftime, but his goal was overturned on a VAR review.
But Suarez added a goal deep in second-half injury time with Messi — who also picked up his first yellow card in MLS for lingering on a corner kick — providing the assist.
Martino said the late goal vindicated his decision to leave both players in the game until the end, saying “both played the whole game because they were fine to finish the game”.
The victory extended Inter Miami’s lead at the top of the MLS standings to 62 points, 10 points clear of their closest Eastern Conference challengers FC Cincinnati with six games remaining in the regular season.
Messi is also pleased that despite his lengthy absence they lead the race for the Supporters’ Shield awarded to the team that tops the overall standings.
Deserved first place
“During the year we were very unlucky with injuries, we were never at full strength,” he said. “For one reason or another we were always missing players and the group always came through.
“Today we are in first place with a big difference and deservedly so, and hopefully we can finish on top for what it means and what comes after that.”
Messi’s two goals, taking him to 14 in just 13 games, put him back in contention for the title of top scorer.
Suarez, meanwhile, has 17 goals and is two behind the current MLS scoring leader, DC United’s Christian Benteke.
After 19,000 fans at Chase Stadium in Fort Lauderdale gave Messi a warm welcome the hosts got a quick scare when Uhre scored with just 58 seconds on the clock.
The Danish attacker controlled a headed clearance from Argentine defender Tomas Aviles and surprised goalkeeper Drake Callender with a blast against the post.
Minutes later, Martino got another shock when Paraguayan center back David Martinez was injured when he intercepted a Philadelphia pass.
The Union continued to put Callender under pressure, but on the other end Messi was starting to take advantage of the spaces to team up with Alba and Suarez.
In the 26th minute, Alba ran the length of the pitch and delivered the ball to Suarez, who set up Messi to cut inside Wagner and score.
Four minutes later, Alba sent a cross from the left into the heart of the box that Suarez let through and Messi converted to make it 2-1.
Messi, 37 and in his second season in the United States, is the fastest player to notch his first 15 goals and 15 assists in MLS, in just 19 games.
© Agence France-Presse
Photo: Michael Pimentel/ISI Photos/Getty Images