"He was purple," Drew Bolli said. "His eyes were rolling back and he was gasping slow breaths."
At that moment another passerby, a woman known as Rhonda - on her way home from work at the nearby New World supermarket - suggested CPR.
Watson was in full cardiac arrest, which is different to a heart attack where blood flow to the heart is blocked. A cardiac arrest is when a person's heart stops beating.
Only six out of 40 people treated for cardiac arrest by St John each week survive to hospital discharge.
Palmer, a trained lifeguard at Pukehina Beach in the Bay of Plenty, rolled Watson on to his back and began CPR compressions.
Some of the young men, on their way home from a concert in Auckland, had completed first aid training though none had used it in a real-life situation.
"My heart was pumping," Blake Bolli said of the October 9, 2016 event. "It was real. He was still with us but we were running out of time."
Two police officers called to a nearby domestic dispute heard the crash and raced to the scene.
But the group needed a defibrillator to shock Watson's heart back into action.
At the same time police were arriving on the doorstep of Watson's partner of 28 years, lawyer Susan Woodhouse.
She was cooking dinner and expecting Watson home any minute with Boo the dog from their run at Minogue Park. Watson was in training for the World Masters Games.
The police explained there had been an accident. Woodhouse asked: "How bad is it?" The answer: "They're working on him", filled her with panic.
She was taken to the scene but kept away from the action, as the young men and police took turns compressing Watson's chest, keeping the blood circulating and oxygen travelling to his brain.
Suddenly Rhonda remembered there was an Automated External Defibrillator at New World. Police raced to the supermarket, about 500m away, and retrieved the device.
"We shocked him four times," Palmer said. "We did 20 minutes of CPR."
Thankfully two St John Ambulances arrived and Bryan Ralph, one of the emergency medical technicians, took over.
Watson was rushed to Waikato Hospital's emergency department where shocked doctors put their colleague into an induced coma.
They performed an angiogram which showed a blockage in the lower left artery of his heart - known as the widow-maker.
Cardiothoracic surgeon Dr Adam El-Gamel performed an advanced surgery where Watson's heart did not have to be put on a bypass machine.
It meant Watson's recovery was much quicker - he went home after a week and spent three months recuperating.
Watson and Woodhouse tracked down the seven good Samaritans and there was an emotional reunion late last year, and another one last Monday, on the one-year anniversary of the crash.
Not only did Watson survive, he suffered no brain damage, made a full return to work and came fourth in his age group in the 2.5km ocean swim of the World Masters Games in April.
"They saved my life," he said.
"Had it not been for people who had the courage to stop, who had done CPR training and got on and did it, and for the fact a lady knew where the nearest defibrillator was, and the police helping, I wouldn't be here talking with you."
He backed New Zealand's inaugural Restart A Heart Day which is tomorrow, supported by St John, the Heart Foundation, Wellington Free Ambulance, Fire and Emergency NZ, and the Health Promotion Agency.
The campaign is aimed at getting more people trained in CPR to increase the survival rates of people who suffer a cardiac arrest outside a hospital setting.
