B737-800
Flight Crew Air Transport Pilot (ATP)
Conflict Ground Conflict; Critical
General None Reported / Taken
Procedure
[In pre-dawn darkness] MMMX ground control cleared us to push and release 'Short of Bravo; Facing Bravo.'  I passed those instructions to the ground crew; and they read it back to us correctly. We stopped; were cleared to start; and I cleared the ground crew to disconnect. The nose of our aircraft was over the ground vehicle roadway painted on the ramp; but not on or over Bravo.  During the start sequence the First Officer; said; '[my name]!' and pointed to the left.  A B747 was in a high-speed taxi; and the right wing tip and large winglet appeared to be heading right toward our cockpit.  The ground crew was still there (but with the headset disconnected) prior to the salute; and our #2 engine was not yet up to idle.  Our only option to avoid decapitation would have been to unbuckle and hit the deck. A radio call would be useless due to the speed of the B747 and because of how quickly this event took place.   Just then we noticed the green nav light 'moving on the windscreen' and not on a collision course.  We watched the large winglet pass ten to fifteen feet in front of our cockpit.  It is unknown whether or not the [B747] crew saw us; or; due to the darkness; whether or not the [B747] Captain was on the Bravo centerline.  (That entire area is regarded by many pilots as a 'black hole.') I made a radio call to MMMX.  For your reference; please see Jeppesen MMMX charts 10-7Z; 10-9; and 10-9B. I would suggest that the MMMX ground crews be instructed to release our aircraft at least 20 feet prior to the painted ground vehicle roadway northwest of taxiway Bravo.
[Report narrative contained no additional information]
B737-800 flight crew reported they were parked near Taxiway B after pushback and were almost hit by a B747 taxiing past them.  Darkness was a factor; and the crew suggested push procedure should not position them that close to the taxiway.