There are various synonyms for the phrase "lose all his fight," which denote a loss of will, determination, or enthusiasm. Some alternate phrases include "throw in the towel," "give up the ghost," "wave the white flag," or "call it quits." These expressions imply a surrender or resignation to an opposing force or circumstance, often after a period of struggle or conflict. Other equivalents could be "lose heart," "succumb," "fall apart," or "breakdown." Regardless of the phrasing, each term conveys a similar sentiment of defeat or exhaustion, representing a moment when one's spirit or motivation is depleted.