What would win? Oh, it's no bother asking you lot since it happened. Portugese 40 Spanish soldiers armed with Rapiers and Daggers fought a Japanese force 1000 or so strong Spanish took 10 to 20 casualties while Japanese losses were in the hundreds. [url=http://en.m.wikipedia.org/wiki/1582_Cagayan_battles]Wiki article[/url] This is the only battle to ever take place between European Swords and Katanas. So, I guess Rapiers really are the better dueling sword, and European Fencing proved to be better than Japanese Martial Arts.