Savage's main and quite possibly only upper hand is superior strength, while Saesee Tiin has far more finesse and elegance incorporated into his duelling techniques.
As far as Force power goes, I guess Savage could win telekinetically. He has thrown about two or three dozen droids or so as well as Anakin and Obi-Wan to the ground, while Saesee Tiin has hurled a droid four kilometers.
I had to run a Google search on Savage Opress to figure out where he was from. Sorry to say it but I watched 3 episodes of the Clone Wars series and I didn't like it. The only two things I remember from it are Yoda toying with Ventress by taking her lightsabers away and Kit Fisto doing very well against General Grievous.
But I did just watch a clip of Maul defeating Savage in less than 10 seconds. If Maul could best Savage so quickly then I think Saesee could take the victory here as well as I see Saesee and Maul being fairly close to one another in skill.