Denzel Washington was fired up, going full “Training Day” as he let loose on a group of paparazzi … and possibly some autograph seekers … who clearly pushed the wrong buttons.

Check out the video … the actor was all smiles, posing for pics outside NYC’s Museum of Modern Art on Wednesday — but it seems at least one person in the overzealous crowd crossed a line … and Denzel didn’t hold back checking that person … in what appeared to be a heated exchange.

You can’t catch most of the convo, but you can hear Denzel pretty much warning them to chill out and wait patiently and respectfully … saying they’d get a chance to see him on the flip side — or maybe not, depending on their behavior.

It’s not super clear what exactly set Denzel off — he’s usually cool, calm and collected IRL –but the whole exchange felt like a throwback to his iconic “King Kong” scene from the 2001 classic, “Training Day.”