Don't know if this is a troll post since its your first, but i'll be nice and think you're genuinely wondering. The answer is: of course!
This applies to all sports. Lebron was/is young in the NBA, but he's one of the best players in the league, if not the best. Look at the NFL and all the rookies this year that are tearing it up.
People are born with genes that naturally allow them to be more athletic and gifted in certain areas. BJ Penn is a great example as someone born for the sport, as is GSP. Of course they have to work hard, but not as hard as say...Kenny Florian would have to to be successful.
So yes, someone with little experience can definitely win depending on how hard they work and how lucky they are as well.