Richard Marx heroically fought off and restrained an out-of-control passenger during a flight from Vietnam to South Korea ... and his wife, Daisy Fuentes, captured the whole ordeal.
Daisy took a bunch of pics as Korean Air flight attendants and the '80s hitmaker teamed up to take down the man. You can see Richard was throwing elbows and even holding the rope tied around the guy.
According to Daisy and Richard ... the flight crew was "completely ill trained" for combat. One of the flight attendants had a taser, but had no clue how to use it ... at least that's how Daisy saw it.
She says they battled the attacker for 4 hours, and 2 passengers and a crew member were injured. Seoul police arrested the guy when they landed.