User blog comment:Gibbz33/Who do you think is the 7th shichibukai?/@comment-4899461-20140221203656/@comment-7890302-20140222042727

Yeah, Enel was physically stronger then even Zoro, and he lost because he became bigger, and gave Luffy 10 tons of gold, to add to an already extremely powerful attack.

Enel is, while physically weaker then Lucci, was stronger then Kaku.