More context would be helpful to make sure we understand what you're asking. Victory is is a noun and it's possible that it could be followed by a prepositional phrase that starts with "over", but It would be more common to see "victory" used like this: We had a victory against our rival. "Win over" is a verb phrase that is usually used to describe gaining the approval or affection of another person or group. At first they didn't like us. But we won them over. It can also be used to describe persuading a person or group to agree with a point of view like in Lerato's example.

Win over- is to persuade (someone) to accept and support something (such as an idea) after opposing it. Eg.They eventually won him over with some persuasive arguments.