"Iron Man" Becomes Karate Kid

Posted May 8th 2008 1:11PM by TMZ Staff

Former drug addict-turned-"Iron Man" Robert Downey Jr. is riding a new high these days -- and has the kicks to prove it.

The 43-year-old box office superhero (left) channeled his inner Ralph Macchio while practicing martial arts with an instructor in his L.A. driveway on Wednesday.

Is Mr. Miyagi in the Avenger Initiative, too?!