Don't have time to debate this since I am preparing a damn huge thread.
But I go with draw. Why?
Because Hiruzen was her teacher, she was her student. They know about their abilities, yet Hiruzen was dead when Tsunade created Genesis Rebirth and Strenght of a Hundred.
Basically, of all the ninjutsu thrown at her, what we've seen until now to be able to take her down (not kill her, please note that) was Mokuton. Meaning a Senju ability against a Senju, lol.
And she still kas Katsuyu. While Enma attacks Tsunade, Katsuyu attacks the third.
And Katsuyu has been shown to be larger than ENMA.
Plus, adamantium is a fictional metal. While Enma can transform in adamantium, Katsuyu has been shown to take high levels of difficulty.
So this is draw because Hiruzen would put a great fight via ninjutsu, but he won't be able to kill her as she regenerates.
This is done like in 2 minutes.
As I've said for the moment I don't have time to debate on this. A wall of text concerning Tsunade awaits me. O_O
Edit: It was so nice to see my name mentioned when it comes to Tsunade. ^^