AOW workflow processing a record more than once


I have created a workflow with below rules:

  1. When lead status is not contacted
  2. It is assigned to admin and related to a particular telecom circle based on phone number
  3. It is related to one particular product

It does below action:

  1. Assign lead to a user among users exist in security group in round robin fashion.
  2. and update created by with assigned user.

I have attached screen shot for clear understanding.

The issue is: This work flow processes one single record more than once and View change log shows: Lead assign from Admin to some user and at same time again assign from admin to another user.

Can someone please help?