Why did Jango Fett jump in the arena to engage Master Windu?

Master Windu was a very powerful Jedi Master (even Count Dooku couldn't stand a chance against him) and this fact should be popular among the bad guys if not across the Galaxy. What made Jango Fett think that he could take out Master Windu all by himself? Yes, he was flying and Windu was on the ground, but this hardly matters in a universe with The Force.