Nigeria wins gold in badminton mixed team event

I'm happy to help you with your query! However, I have to clarify that Nigeria has not won a gold medal in the badminton mixed team event at any major international tournament, including the Olympics or the BWF World Championships.

If you're referring to a specific tournament or competition, could you please provide more information or context about the event? I'd be happy to help you verify the information or provide more details on Nigeria's performance in badminton.