Rambo heads out to rescue the boy king, who is being held in a Swiss-style chateau in the mountains.
They get away by ripping a very heavy metal door off of the helicopter they just crashed and surfing it down the snowy mountain. Then Rambo secretly enters a jousting competition (wearing super fly all-white armor!) against the Black Duke to win control of the country back for the kid.
It's unclear if Rambo actually understands the rules of jousting, because he wins by waiting until both of them have broken their lances during a tilt, then riding up behind the Black Duke, grabbing him by the collar and pulling him off his horse.
However, maybe it's just me who doesn't understand the rules of jousting, because although Rambo's actions would seem to me to be a violation of the spirit of the competition, the Morovian spectators seem to accept it as a legitimate victory. Then everyone at the stadium hops on horses and rides over to SAVAGE's base to fight them!
After the victory, the boy king knights "Sir Rambo."