Dramatic CCTV footage has shown the moment a rail worker pulled a passenger from the tracks one second before a train was about to hit him.

John O'Connor, a supervisor on San Francisco's Bay Area Rapid Transit (BART), was helping manage crowds at the Coliseum station in Oakland when a man fell on to the tracks.

O'Connor's remarkably quick reaction meant he managed to pull the passenger back on to the platform just as a train pulled into the station.

Colleagues have since described the rail worker as a hero, but he said he was just doing his job.

“John is a transportation supervisor and has worked at BART for more than 20 years. An amazing rescue," the rail operator said.

Speaking to reporters, O'Connor said the CCTV footage appeared much slower than it actually felt.

“I was fortunate that God put me there and he got to see another day. When I spoke to him later, I told him, 'Hey, pay it forward,'" O'Connor was quoted by CBS SF as saying.

Fellow passenger Tony Badilla filmed O'Connor hugging the rescued man as those on the platform applauded.

“I was watching John work as I was waiting for the train before this happened," he said.

Badilla added: “He demonstrates passion in his work and we all should extend our gratitude to those we encounter who do the same on a daily basis."