rear guard action

Translations
арьергардные действия
The company fought a rear guard action to protect its market share against new competitors.
Компания совершила арьергардные действия, чтобы защитить свою долю рынка от новых конкурентов.
Definitions
A rear guard action is a military maneuver in which a small force stays behind to delay, defend against, or slow down an advancing enemy while the main body of troops retreats or regroups. The term is also used metaphorically to describe efforts to resist change or prevent the loss of something, even when ultimate defeat seems likely.