If it was just a straight-up 1v1 match between a fresh Spartan and Elite, with nothing else but swords....It'd be a close one.  The Elites have had more experience with the weapons, but the Spartans are very resourceful.

Then there are many unknowns to factor in as well.

-Lighting

-Terrain

-Personal strength *Remember, not all Spartans and Elites have the same personal Strength, much like us normal human beings.*

-Chance *You never know, the Elite/Spartan could accidentally misstep and place him/herself in a disadvantage*