Yes, even though Wlad already beat Peter, he would have to beat him again. The reason being that Wlad beat Peter when Peter was a prospect, now Wlad who is the #1 ranked fighter in the world would have to fight Peter who is now #2 in the world to fill the vacancy.


Also the #1 fighter fighting the #3 fighter can fill a vacancy when there is little difference between the quality of the #3 fighter and #2 fighter.