Winning a Ranked match wont come easy. It takes knowledge of your character and knowledge against your opponent. The more you play the easier wins will come because you will learn the tendencies of online players. People are creatures of habit and you will notice that people repeat the same things over and over again online.
You only need to win once to earn this achievement.
For Fulgore the best thing to learn quickly is his footsie game. He plays very much like Ryu from Street Fighter. His crouching medium kick is very fast and his uppercut is incredibly damaging. Shadow blade dash is a really good way to catch people by surprise and start a combo. Always end your combos with the uppercut or Shadow uppercut (until you are better of course).