I played in a Brazilian Championship (Interclubs) in Campinas, 1989 (http://www.brasilbase.pro.br/bre1989.htm
In the 1st round, my opponent was a 8 year-old boy.
- It's ridiculous! I don't want to play with a kid! I'm 22 and I play since my 8!!! - I saw for my team mates.
- Be, careful, Helder. - answer my friend José Roberto Morau - This kid is FIDE master, because he was 2nd place in a World Championship for kids in Puerto Rico (see in http://www.tabuleirodexadrez.com.br/rafael-leitao.htm)
His name: Rafael Duailibe Leitão.
Our game was 5 hours of duration... 😞 :'(