When Dr Michael Shannon saved Chris Trokey's life when he was born premature more than 30 years ago, he could never have known that the favor would one day be returned.

But in 2011, Dr Shannon was trapped in his burning SUV after it was T-boned by a semi-truck, when Trokey, now an Orange County Fire Authority paramedic, worked to pull him out alive.

Their incredible story was shared by KTLA after the pair both participated in a fundraiser for childhood cancer in Rancho Santa Margarita, California on Sunday.

Reunited: Chris Trokey, second left, saved the life of Dr Michael Shannon, pictured center, with fellow paramedics (pictured) in 2011 - thirty years after the doctor saved his life as a newborn

The two men greeted each other like old friends before having their heads shaved for The St. Baldrick's Foundation.

They recalled how, exactly four years prior, Dr Shannon had been driving on Pacific Coast Highway in Dana Point when he was hit by a truck and pinned beneath it in his vehicle.

Firefighters from Paramedic Engine 29 - of which Trokey was a part - responded to the fire and managed to stop the flames and cut him out of the car.

But Trokey was unaware of who he had saved until he went to the hospital, where Dr Shannon spent more than a month recuperating.

'I was like, "Oh my gosh, Dr. Shannon?"' Trokey told KTLA.

Wreckage: Trokey was one of the paramedics who treated Dr Shannon and rushed him to hospital - where he spent more than a month - after he was hit by a semi-truck and trapped in this burning SUV

Firm friends: The two men caught up last Sunday when they both took part in a fundraising event

They had met many years before - when Trokey was born weighing just 3.2 pounds and his pediatrician - Dr. Shannon - stayed with the baby around the clock to make sure he survived.

'It's amazing to watch them all grow up, but to have one come back in your life, on a day you really need it, that's really incredible,' Shannon said.

He added to Yahoo: 'I do believe that things are supposed to happen when they do. I see examples of this almost daily in my life and practice.'

Trokey said that Dr Shannon is now pediatrician for his own newborn son.