Hitler was present at Berlin’s Olympic Stadium as Owens and Long contested one of the Games’ greatest long jump finals.

After a see-sawing battle, Long matched Owens’ leading distance of 7.87m with his penultimate attempt, to the delight of the home fans.

But Owens dug out his best when he needed it most, responding with 7.94m, to move clear of Long once again.

Long produced a foul on his final attempt, but his performance was good enough for silver and a first Olympic long jump medal for Germany.

Owens, with his title already assured, created further history with a final leap of 8.06m – setting an Olympic record that would stand for 24 years.

Long, putting aside his own disappointment, instinctively leapt into the sandpit to congratulate him.

Locked in that moment, alone in their embrace as an appreciative capacity crowd of more than 100,000 people watched on, Owens confided to his rival: “You forced me to give my best.”

Between them, Owens and Long had surpassed the previous Olympic record five times.

“It’s almost like a fairytale – to jump so long in this weather,” said Long in an interview with his hometown newspaper, Neue Leipziger Zeitung.

“I can’t help it. I run to him. I’m the first to congratulate him, to hug him.”

Long’s impulsive reaction caught the attention of the German authorities.

Soon after the Olympic Games, his mother, Johanna, made a note in her diary about a warning from Rudolf Hess, then deputy Fuhrer of the Nazi Party.

Long, she wrote, had “received an order from the highest authority” that he should never again embrace a black person.

He had been noted as “not racially conscious” by the Nazi regime.

The embrace clearly angered the Nazis, who often used powerful imagery to further its own ideology and feared how Owens and Long’s friendship might undermine its propaganda.

In that respect, they were right.

Almost 90 years later, Owens and Long’s friendship is one of the most enduring Olympic stories.

“The gesture of kindness and fairness touched the hearts of many people,” says Kellner-Long.

“Together, Luz and Jesse enjoyed a special friendship that day, demonstrating to the world that in sports and in life, friendship and respect are the most important things, regardless of background or skin colour.”

Stuart Rankin, Owens’ only grandson, is equally struck by its significance.

“I often say that of all my grandfather’s accomplishments at the 1936 Olympics, the unlikely friendship that he struck with Luz Long is the thing of which I am most proud and most impressed by,” he says.

“For them to have forged that friendship, under those conditions, in those circumstances, in that stadium, in the face of Hitler, was just phenomenal.”