Man Collapses in Oval Office, Dr. Oz Steps in to Help, on Video

Dr. Oz is always on call ... because he swooped in to help a man who collapsed during a press conference inside the Oval Office ... and President Trump had a front row seat.

Ya gotta see the video ... Eli Lilly CEO David Ricks is talking about a deal the company signed with the Trump Administration to lower prices on obesity drugs -- when an unidentified man in the background suddenly suffers a medical emergency.

The man falls to his knees and Dr. Oz rushes over ... he helps lay the man down on his back and elevates his legs and feet.

White House staffers start to shoo away the media and then the cameras cut away ... but not before you see Trump standing up from the Resolute Desk and staring down at the stricken man.

Robert F. Kennedy Jr., the U.S. Health and Human Services Secretary, was also in the room when the incident happened.

It's unclear what caused the man to collapse or who he is. It was originally reported the stricken man was a Novo Nordisk executive.

Dr. Oz was previously swooped into action at the Oval Office back in April, when one of his own grandkids fainted while he was being sworn in.