It also could be because Maul spent who knows how much time wandering in the desert going insane while Kenobi was probably watching him from afar the whole time.
Plus, the second Maul mentioned; "No...protecting someone", the fight was already over.
Kenobi was like; "lets ****ing do this" and probably achieved an intense focus the way I did yesterday with a girl. Jk lol
Plus, half of the fight was them changing stances where Kenobi went into the Ataru stance that reminded Maul of Qui-Gon.
I think I remember someone asking Filoni at celebration if Kenobi switching his stance to the Ataru was intentional and I think he said yes.
I'm not sure, I don't have the best memory ever, at least at inconsistent times.
I also remember how in one of Ant's Thread's he showed something on how a book said the Kenobi and Vader fight in ANH had Kenobi having the upperhand although it was referring to the time before they even clashed blades.
I bring this up because in the ANH novel they actually standoff for about a minute where in the film it looks to be like 5-10 seconds and how Kenobi having the uperhand could be referring to the standoff they had before the fight. I guess I'm just trying to make a connection.