My friends are mature enough to understand why I would choose someone more competent than them. Being a good friend would be to tell them straight away the reasons so they can improve.

You choose someone based on their skills not because you hang out with them. The other seemed to be slightly better than OP's friend and in competitions a slight difference has always a huge impact. I wouldn't encourage nepotism.

If you voted objectively then that's a good thing. Your friend can be upset bc they're hurt but you did something right.