Hi, I was playing the Baldur's Gate and I faced one problem...
I've already entered the Ducal Palace and killed the dopplegangers (I also killed Belt and the other duke...may be that's the reason why it's happening).
I'm fighting against Sarevok when a fire ray kill me and a wizard called "Winski Perorata" appears. I used all the scrolls and potions available and he still kills me by one single hit and the worst part is that he only attacks me. The problem is that I saved the game.

Is that normal? I have read that I fight Sarevok for a while and then he leaves.
What can i do? Is there any chance to go back in time?
I wouldn't like to start all over again....