Ted by a slight margin.
The cage would would restrict Matts superior agility which in another environment would give him the win.
In pure boxing ( which Matt would be forced to use in this environment) Ted has a slight advantage. He has displayed an ability to completely shift fightimg styles more than once and to fight using the combat techniques snd styles of other fighters. By contrast in a more open setting the freeform of Matt would have greater versatility with its less formal nature.
A more Open battlefield shifts significantly toward Matt.