This is a match that Jiraiya has. Jiraiya has the original Rasengan which while it’s possibly not as strong as Naruto’s it’s plenty strong. Plus Jiraiya has sage mode. Zangetsu has a lot of knowledge and seems to be strong but his skills don’t cut it here. Jiraiya wins.

But now Zangetsu has a super form that trumps Jiraiya’s. Zangetsu wins.