I am not 100% sure if this is a worlds first, but I didn't see any posts about it and this still seems like a very sweet achievement to get:
Refuge (EU Aegwynn) got A Tribute to Dedicated Insanity (kill anub-10 with no members using toc-25 gear and nobody dying)
Proof: http://eu.wowarmory.com/character-ac...gwynn&n=Zoltan