A frustrated Gerardo Martino admitted Inter Miami fell "too short" after being knocked out in the first round of the MLS playoffs by Atlanta United.

Miami won the first match in the best-of-three series at Chase Stadium, but subsequently lost the next two, being beaten 3-2 in the decider on Saturday.

Bartosz Slisz netted the winner in the 76th minute, but the hosts struggled to find an equaliser that would have forced penalties, with Brad Guzen in inspired form as he thwarted their attack.

It is arguably one of the biggest upsets in playoffs history, with Miami the favourites to lift the MLS Cup after a record-breaking regular season saw them claim 74 points in the Eastern Conference.

"In this last part of the year, we get used to achieving the objectives that we set for ourselves, and we have not been able to achieve the most important one," Martino told reporters.

"If you think about where we were in November last year, obviously there is progress as far as the club is concerned, not just the team.

"If you think about the expectations we had for this playoff, obviously we have fallen too short."

While the loss has come as an obvious shock, Atlanta have actually now won three matches against Miami this season.

Jamal Thiare scored two goals in two minutes to give the Five Stripes the lead in the first half, having also hit the post moments before Miami had opened the scoring.

They face another trip to Florida to face Orlando City in the Eastern Conference semi-finals, and the forward is excited to see what else Atlanta can do.

"It took everyone's special amount of running and giving everything that they got," said Thiare. "Everyone's held each other accountable, fighting when we're basically backs against the wall.

"We didn't want to finish the season like this, so it was a good effort in training, but it was really something that the group discovered along the lines of the last few games. And something great is igniting from all of this."