A 999 call handler brought her own dad back to life after he died while watching TV at home.
Estelle Williams was asleep when her mother Denise started screaming in their London home.
She jumped out of bed and rushed to her parents' room, where she found her dad Eddie had collapsed.
She immediately called an ambulance and started CPR, using the same technique she repeats over the phone as part of her job.
Estelle kept up the chest compressions until a paramedic arrived with a defibrillator, MyLondon reports.
The London Ambulance Service call handler was asleep after a night shift when her dad collapsed.
Eddie was gasping for breath and then stopped breathing altogether as he changed colour.
Estelle said: "I knew he was dead. I have instructed people over the phone on how to give CPR so I knew what I was doing, but you never imagine you would ever need that knowledge to save your own dad."
Paramedic Bethany Grace was the first paramedic to arrive on scene and she asked Estelle to keep giving Eddie chest compressions while she prepared the defibrillator, which gives an electric shock that can get the heart beating again - and it brought Eddie back to life.
Eddie joked that everything in his will is now going to Estelle given that she saved his life.
Eddie celebrated his 72nd birthday this week and his daughter surprised him with a party at the 999 control room where she works. She invited the whole team involved in Eddie's care.
Eddie said: "I don't remember what happened at all but I am thankful to my daughter for saving my life. I am grateful to meet all the angels at London Ambulance Service for helping to save my life. But my daughter… well I've told her, everything in my will is hers!"
Eddie spent a week in hospital recovering after his cardiac arrest and has now been fitted with an implantable defibrillator.
Estelle added: "My dad is such an important figure in my family's life, and I am so grateful to all the team at London Ambulance Service for saving his life so effectively so we can spend many more years with him, and celebrate life."
All call handlers get training in how to do CPR (cardiopulmonary resuscitation) and use a defibrillator, and regularly instruct members of the public in these life-saving skills.
Paramedic Bethany Grace said that arriving to see compressions performed correctly gave instant hope for Eddie.
She added: "These key components in the chain of survival are essential.
"It's extremely rare for a patient to be so unwell and then talking moments later as Eddie was, and this is down to effective CPR and an early shock from the defibrillator."
London Ambulance Service is running a London Lifesavers campaign which encourages everyone to learn simple life-saving skills.
It can take just a matter of minutes to learn these skills but could make the difference between life and death for a person in cardiac arrest. You can learn how to save a life here.
