The 4-year-old is seen in surveillance video on a crowded platform, walking toward a train door when suddenly he slips through the crack.
Other passengers and staff at the Sydenham Station in Sydney were quick to jump into action to rescue the boy, according to Australia's 9News.
The frightening incident reportedly happened in February, but the country's transport ministry released the footage this week in an effort to warn adults to pay close attention to kids during summer break.
“One split second lapse in concentration could see the loss of life of a child and we don't want to see that,” Andrew Constance, the transport minister, said.
Children slipping between the train and platform isn't a rare occurrence. According to the news outlet, nearly 70 children fell through such a gap at train stations in Australia during the past year alone.