Korath the Pursuer (Guardians of the Galaxy) vs MCU Loki. Both are blood-lusted, both are equipped with a single combat knife, and the fight is to the death. Takes place on Ronan's ship and they start 10 yards apart. Who wins and why?

Loki uses his magic to make a fake version of himself, Korath goes for the fake Loki, real Loki sneeks up behind im and shanks Korath in the back of the head

Loki

Way too tricky, and durable (see Hulk thrashing).

I'd go with Loki, he has more feats, might be somewhat stronger and durable, the later being not as much of a factor given that alien and asgardian weapons seem to cut into Asgardians no problem. And can casually catch arrows. Also he is the one of them who we saw use a knife in combat.

Loki loki, this fight alone put him above pretty much of everyone except of Thor, Hulk and Kurse and maybe Ronan.

Loki. Compare Loki with his boss Ronan then we have a fight