overdog 
noun informal
A person who is successful or dominant in their field.Ventura was also a genuine underdog with an outsider's passion for political reform, while Arnold is the ultimate overdog....
- We could build on this forgiving little ceremony with something that panders not just to Utah but overdogs everywhere: The March of Defeated Nations.
- The next is Apple's perpetual role as scrappy underdog - reporters love cheerleading for the underdog without ever pausing to explore why it isn't the overdog.