The fighter was driving past a four-car pile up on the 405 freeway in Los Angeles when he spotted a dazed dad in distress, and stopped to help.

The father was trying to unlock a rear door and free his screaming child when Mosley took over.

"You don't know if the car is going to catch fire, what's going to happen, then seeing there's a baby in there..." he told local news station KCAL9. "The baby was crying and bleeding, his neck was bruised."

Mosley's girlfriend called 911 and the infant's mother, and couple stayed with the dad and his baby until paramedics arrived on the scene.

The fighter then followed the ambulance to the hospital with the baby bag he had also retrieved from the burning car.

"He (the father) was crying and saying, 'You guys are like an angel', and, 'Thank you for helping me, and being there for me and protecting my son.'"

Mosley also kept his Twitter followers updated on the drama, writing: "4car pile up on the 405 right in front of me. My quick reaction time saved my family. Hope the baby & the father we stopped to help are ok.

"My girl got blood all over her jacket from the baby. We are at the hospital to meet the mom to give her the baby bag. Hope they all ok. Damn."

He later added, "The baby & the dad are ok! We're really happy. Turns out his wife is 7 months pregnant. So it's a real gift he & the baby in the car are ok."

Mosley, 44, also handed the grateful dad tickets to his upcoming fight against David Avanesyan at the Gila River Arena in Glendale, Arizona on 28 May (16).