CAN someone use a Second-language as perfectly as his native one?

A couple of days ago,while looking up something on wikipedia,I found an Chinese article which was definitely Not written by a Chinese.I am so sure for he made some mistakes even a Chinese pupil would not make.But to my surprise,he could use so many Chinese idioms,some of which were even unfamiliar to me,and what he wrote was under a constant attempt of being literary.Taking a rough look of his essay,you may consider him a Chinese language master;But some trivial mistakes betrayed him!So,I am wondering whether there are or had been some who lived in his own country while could use a second language perfectly that even a well-educated native speaker deemed him a Really Master and felt inferior to him?