eleventh hour

at the eleventh hour (at the last minute; just in time, at the very last opportunity; ) — ≅ в последнюю минуту; в (самый) последний момент

Example 1: You should not have waited until the eleventh hour to finish your project. — Не надо было тянуть с заданием до последнего момента.

Example 2: At the eleventh hour, the soldiers arrived to help their comrades defeat the enemy.

compare
[in the nick of time]

see also
[have a narrow escape]
[a close call]
[saved by the bell]