Arsonists torched a car belonging to Cory Hutchings and his partner in an early morning attack outside his house.
The former world surf lifesaving Ironman champion raced outside the Gisborne home he shares with Shelley Donaldson about 2am today to put out the flames with a garden hose.
Ms Donaldson said she was "gutted" at the loss but grateful the flames from the burning car did not reach her home where four children were asleep.
She had bought the 1996 Subaru Impreza five-door hatchback as a first vehicle for her stepdaughter.
The blaze severely damaged the car and is being treated as suspicious, probably arson.
"My partner Cory [Hutchings] and I heard the neighbours yelling Cory's name just before 2am," she said.
"We quickly jumped out of bed and went to investigate. When we opened the blinds we saw the car was engulfed in flames.
"The northwesterly wind was pushing the flames towards the front rooms of our house where the four children aged between 3 and 16 were asleep."
Ms Donaldson called 111 while Mr Hutchings ran outside and started to tackle the fire with a garden hose.
"The fire service arrived within a few minutes and put the fire out quickly. As well as the Subaru, which was not insured, our front fence was blackened and there was some heat damage to my car, which was parked adjacent to the Subaru."
Station officer Ed Hindmarsh said the cause of the fire is definitely suspicious.
"When we got there the fire had a good hold in the engine compartment and in the front seats. The damage was extensive."
Firefighters used a couple of hose reels to put out the flames.
Specialist fire investigator Derek Goodwin examined the wrecked vehicle this morning and police have an inquiry under way.
The vehicle cost Ms Donaldson $1500 and is a total loss.
"We saw that the passenger side door had been left open, so someone had obviously been in there," she said.
"It was a real shock to see that car burning. Not what you want to wake up to and see out your bedroom window at 2 o'clock in the morning."
A reward has been offered for information about the fire and Ms Donaldson can be contacted on Facebook.