New York Red Bulls blew a lead to be bundled out of the MLS playoffs by first-time participants Cincinnati 2-1 with Brandon Vasquez netting an 86th-minute winner on Saturday.

Lewis Morgan, who scored 14 goals in the regular season, had put the Red Bulls ahead with a rifled strike from outside the box in the 48th minute at Red Bull Arena.

But Cincinnati replied with two goals in the final 15 minutes to secure their spot in the Conference Semifinals where they will face top seed Philadelphia Union. Fourth-year franchise Cincy had finished last in the Eastern Conference during its previous three campaigns.

Cincy thought they had an equalizer in the 60th minute when the Red Bulls failed to clear a long throw and Junior Moreno's strike was deflected in, but that was by an offside Jeff Cameron.

But the visitors found an avenue back when Red Bulls defender Andres Reyes clumsily brought down Alvaro Barreal, with Luciano Acosta stepping up to send Carlos Coronel the wrong way with the 74th-minute penalty.

New York were stunned when Cincy took the lead with less than five minutes of regulation time left as Vasquez sidefooted home substitute Sergio Santos' left-flank pass.

Cincy goalkeeper Roman Celentano denied Aaron Long's 88th-minute header, while Red Bulls defender Sean Nealis headed over in stoppage time.

LA Galaxy moved into the Conference Semifinals where they will face LAFC after a 1-0 home victory over Nashville at Dignity Health Sports Park.

The hosts thought they had gone ahead in the 50th minute when they raced forward in a four-on-two situation with Riqui Puig laying off for Javier Hernandez to fire home but the goal was disallowed on review after a Ronald Araujo foul in the build-up.

Pink-haired Araujo, who hit the post with a wayward 60th-minute cross, made amends when he headed in Samuel Grandsir's cross from the byline on the right side.

Galaxy could have added another but Nashville goalkeeper Joe Willis made saves from Riqui Puig and Kevin Cabral late.