If you don't have an employment contract, you are an employee at will. As an employee at will, your employer may suspend or terminate you at any time, for any reason, including for being involved in a physical altercation, even if the other party to the altercation instigated it. You may be able to press charges against your ex, or even sue him for your injuries and other losses or costs, but that does not prevent your employer from suspending you.