Charlotte FC squeezed past Lionel Messi's Inter Miami 1-0 to sneak into Major League Soccer's playoffs on Saturday in a nail-biting final day of regular season action.

A 13th-minute goal from Charlotte's Colombian striker Kerwin Vargas was enough to seal victory for the North Carolina franchise, which had drawn 2-2 with Miami in Florida on Wednesday.

Messi was back in the starting lineup for Miami for the first time since September 20, when muscle fatigue left him sidelined and effectively torpedoed Inter's hopes of mounting a late-season charge into the playoffs.

But Messi's return to club duty after the international break was not enough to inspire the Florida club against Charlotte, which finished the season in ninth place on 43 points to advance to the wild card round.

Charlotte's victory secured one of the two final remaining playoff places up for grabs in the Eastern Conference heading into Saturday’s last round of fixtures.

The other spot was grabbed by the New York Red Bulls, who reached their 14th straight post-season in the most dramatic way possible, with a penalty four minutes into stoppage time securing a 1-0 win over Nashville.

The Red Bulls' season looked to be ending in disappointment with the team struggling to break down Nashville. 

Had the score stayed at 0-0, Montreal would have crept into the playoffs just ahead of them.

But with time running out at Nashville's Geodis Park, Panama international Anibal Godoy made a clumsy lunge on Red Bulls winger Luquinhas just inside the area and referee Lukasz Szpala pointed to the spot.

Red Bulls defender John Tolkin then stepped up to coolly slot home the penalty to send New York into a wild card clash against Charlotte on Wednesday. 

"I've not really taken any professional penalties but I wanted it," the 21-year-old Tolkin said afterwards.

"I was more nervous about my mum -- I knew she'd probably be having a heart attack watching at home.

"This is just a testament to all the hard work we've put in this year. Everybody deserves it. We're ecstatic right now.

"We came into the game knowing it's win or go home and we didn't want to leave anything out on the field."