"Empowering Advanced Learners of English in Business and Academia - TOEFL / ESL / EFL"
To be saved at the last second by time expiring or by someone intervening. This is a boxing metaphor.
Context : Social Life, Sports Category: Idiom, Metaphor Semantic: save
"Saved by the Bell" was also a popular television show in the US between 1989 and 1993.
The boxer was saved by the bell in round 8. (literal)
Thank god I was saved by the bell when you showed up, I was about to be attacked by those guys.