60's-70's Martial Arts movie search

I saw this martial arts movie once on TV waaay back when, and its stuck in my mind ever since. Casually I've looked for it now and again, but can never seem to find it or its title. So I'm asking for a bit of help here.

It was about a trio of friends who were martial arts experts (duh!). An American male, an American female, and their male Asian friend. Of note here is that the Asian friend has a very distinctive Chi yell when fighting.

They fall afoul of some bad guy, interfere with his plans, and so he has them captured and separated, telling each that the other 2 are dead.

Believing each other dead, the 3 friends are finally pitted against each other in a blind-folded arena contest, all at the same time, to the death. But during the combat with each other, the unique chi yell of the Asian is recognized by his friends, and they realize that they are back together as a team and commence to kick-butt on the bad guy.

For nostalgia sakes alone, I'd like to see it again.

If anybody recognizes this movie, I'd really like to know.