Russell Piper a project manager for Morgan Lovell was working on a construction site on Uxbridge Road when Stephen Headley went into cardiac arrest.
The remarkable reaction from Mr Piper who put his first aid skills to work, called 999 and talked to ambulance control, with his mobile phone on loudspeaker, while administering CPR, saved this man's life.
He was helped by another first aider on site and the two men took it turns to give rounds of CPR before paramedics arrived with an automated external defibrillator (AED).
The 54-year-old was recognised as a ‘Workplace Hero’ at the St John Ambulance Everyday Heroes awards on Wednesday (September 7).
Mr Headley of Welwyn Garden City, Hertfordshire, survived the incident in February 2014, but suffered brain damage and was unable to walk or talk for a long time.
He has only recently made a comeback which allowed him to put Mr Piper's name forward for the award.
'Without him, I wouldn't be here today'
Mr Piper said: “I feel extremely proud to be recognised in this way, particularly after hearing the other inspirational stories at the awards ceremony. It really brings home how important it is to learn first aid and I’ll continue to go out of my way to encourage more people to learn these skills.
“It was also wonderful to have Stephen there at the ceremony. He’s looking really well and has made a huge amount of progress in the last year.”
Following the incident, Mr Piper visited Mr Headley in hospital, and provided help and support to his to his partner.
As well as this, as a direct result of his actions the company now offer AED training to staff and defibrillators are available to the site teams.
Mr Headley added: “I’m over the moon Russell has won this award and I had a tear in my eye when he took to the stage to accept it.
“He has done so much for me - I can’t thank him enough. He’s an amazing man; without him I wouldn’t be here today.”
There were 10 other inspirational winners at the awards ceremony, which was hosted by presenter Myleene Klass and attended by Sophie, Countess of Wessex.