The most important person; the chief; boss: Who's top dog around this place?(1900+)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with top-drawer
Of the highest quality, importance, or rank, as in The musicians in this pick-up orchestra were top drawer. It probably alludes to the uppermost drawer in a bureau or chest, where the most valuable objects (such as jewelry) are usually kept.
[ c. 1900