The little boy had been left home alone by his mother as a punishment while she took his siblings for a walk.
The youngster climbed onto the window sill to see where they had got to but slipped and was left hanging from the outside of the open window.
Fortunately, a local security guard, named only as Mikhail, spotted him and raised the alarm by shouting for people to help.
And a group of neighbours rushed outside with a blanket – just in time to catch the boy as he lost his grip and fell.
The boy fell through the blanket, which ripped, but it managed to slow him down enough to save his life.
He is being treated at a nearby hospital for internal bruising but is expected to make a good recovery.
Witnesses said he tried to get to his feet after his fall and kept repeating that he wanted his mum.
Dmitry, a neighbour who works as a surgeon at a local hospital, gave the boy first aid while they waited for a hospital.
The shocking moment the young boy is seen hanging outside the window
Neighbours saved the boy by catching him in a blanket
He said: “His mother rushed up with two kids, while he was still in my hands. She did not know what to say or who to, she was shocked, you can understand that.
“We shouldn’t judge her. When she arrived, the boy said to her: “Mummy, I just wanted to go for a walk.”
Witnesses said that before the boy fell, he was calling for his mother, asking for her forgiveness and promising to behave in future.
Police have launched an investigation into the incident but have not yet made any comment on their findings.