Interesting, since Oda wanted Tsunade to fight [Deva] Pain originally in Konoha but his editor had him cut it to save time.
Tsunade hasn't shown the same espionage skills as Jiraiya, presumably she's very good but without knowing exactly what she's got, we have to infer she'll do worse here. She'll be found out by Konan, to whom she does not know as well. Jiraiya neutralized her because he knew how to stop her paper jutsu. Will Tsunade find out how? Sure, but to me that's the difference between a short skirmish and a drawn out, Deidara v. Sasuke style battle.
Pain is definitely interrupting Tsunade here, I think she'll do much much better against the Animal Path, the Human path & Preta Path. She may struggle landing solid blows but she's built to take all of them on.
Once we get to her using her seal's full power & the Full Six show up, I think she's cooked. If she doesn't retreat, she's being manhandled by Deva and having her soul stolen eventually by Human.