Don't push Ronda Rousey unless you're looking to get slammed to the ground ... that goes for guys too.

The executive producer of "The Ellen DeGeneres Show" -- Andy Lassner -- learned that lesson the hard way when he got a little too chummy with the UFC champ ... seeming to get under Ronda's skin after giving her a push before their demonstration.

She didn't just take him down, she performed her famous armbar on him ... getting him to tap out a couple of times after he was unable to break free from the painful move.

She really is the best.