Even battle. Nightwing is much more agile while Iron Fist edges him skill.
The Iron Fist attack will likely be dodged while Nightwings gadgets can net him a tactical advantage.
Mr.V
Iron Fist more times than not. He's Dick's physical superior in most ways except agility but he's no slouch at that either. He's also has the Iron Fist which is a little bit of an overkill if he uses that.