What is the shortest known on the board game played between GM rated players that ended with a checkmate? "Shortest" does not mean the game has to be very short.
Note: Edited this question twice clarifying some ambiguity.
Keres-Arlamowski 1950, comes very close
I heard Mr Arlamovski was an IM at the time - but given Keres' level, and the fact that there was much fewer IM's back then - probably puts the game into the GM level category.