I don't think so.I think Curze would come out on top in a 1v1 because he is very capable of killing a primarch both physically and mentally (ask Vulkan: oh wait, you can't!) It's very close to call, but Curze would sneak up on Corax and maul him.
It's quite a tough call. If Corax can have the initiative and sneak Curze, then Curze is dead. But if Curze can play on the moral of Corax, he can have a fair shot on Corax and kill him.
But on Istvaan, Curze had a gold opening, and Corax flew away and escape him anyway.
In every fight he fought, Curze never fought fairly. His most impressive feat was when he lured Guilliman and the Lion and almost win. Yet, his main attack don't resided in his fighting skill but in a trap he setted before the fight.
The problem is, Corax doesn't fight fairly. They are like Gork and Mork : the god of brutal cunning against the god of cunning brutality.