I'm no Sasuke fan, and I love Jiraiya, but Sasuke takes this without a doubt.
1. Jirayia can't dodge Amaterasu
2. Sage Mode takes too much time
3. I think Sasuke's Sharingan allows him to control summons even without their will, like when shown with Manda. This might only be possible on summons that the user already has a contract with, but if he's able to do it, Jiraiya is in big trouble.
4. Susanoo would be very hard to break through, and I don't think Jiraiya would be able to.
P.s. If Jiraiya manages to summon Ma and Pa and enter Sage Mode, he has more chance to win this fight