Bradley Lowery: Tragic mascot's bond with England striker touched hearts across the world
And Bradley’s cheeky smile and “energy” drew Defoe to him the first time they met before a match, with the pair making an instant connection.
In an emotional press conference in Bradley’s final days, Defoe said: “He will always be in my heart for the rest of my life.
“There isn’t a day that goes past when I don’t wake up and check my phone or think about little Bradley.
“His love is genuine and I can see it in his eyes when he looks at me.”
When the footballer said he was “blessed” to have known Bradley, it was a sentiment shared by hundreds of thousands around the world.
A request for people to send Christmas cards to the boy with big brown eyes was backed by 250,000 people.
And those supporters followed his progress on social media as he bravely fought the pain to undergo gruelling treatment at the Royal Victoria Infirmary, Newcastle.
It was a beautiful photograph of Bradley falling asleep on his hospital bed as he cuddled his hero Defoe that touched the nation.
Where once Bradley had been in awe of Sunderland’s top scorer, he came to accept his relationship with Defoe as normal, calling him his “best friend”.
The Football Association invited Bradley to be a mascot for the World Cup qualifier at Wembley against Lithuania on March 26, after which Defoe was unexpectedly called up into the squad at the age of 34.
Bradley was there to see his friend score his first goal in an England shirt for four years.
Captain Joe Hart let Bradley and Defoe lead the team out onto the pitch and Bradley covered his ears from the cacophony of the 78,000 crowd.
Defoe later said he struggled to keep his emotions in check as he walked out hand-in-hand with his young friend.
It was a fairytale occasion and Bradley said afterwards: “I have had an amazing day and I will never forget Jermain because I love him so much.”
Less than 24 hours after the VIP experience, Bradley was back in hospital for more treatment to extend his life.
His family and well-wishers organised a huge party for his sixth birthday on the local cricket pitch, with a funfair and fire-eaters.
Defoe and Sunderland goalkeeper Vito Mannone were there to join the celebrations, attended by scores of young people from the village.
It was a landmark birthday his family had been desperate for him to live to see.
Bradley was diagnosed with neuroblastoma when he was 18 months old after a tumour was found above his left kidney.
He pulled through despite being resuscitated in hospital several times during treatment which lasted two years.
His parents Gemma and Carl were overjoyed when he got the all-clear but cancer returned and had spread in July 2016.
Scans at Christmas 2016 revealed his cancer was terminal.
His family had started to fundraise to get Bradley groundbreaking treatment in the US and Everton FC had pledged a remarkable £200,000 towards the cost.
Those plans were shelved by the diagnosis, after £700,000 was raised.
Football fans around the country had already taken him to their hearts, chanting his name at games and holding banners saying: “Cancer has no colours.”
He was a guest of honour at the BBC Sports Personality of the Year bash and he was given Match Of The Day’s goal of the month award in December after scoring in the warm-up of Sunderland’s game against Chelsea.
Fundraising even united Newcastle and Sunderland fans as they came together to help Bradley.
His family will set up a foundation to help other children going through the same ordeal.
In an interview with Tyne Tees TV in February, his mother said: “I feel Bradley has only had a short time on this earth.
“He has done more in his five, six, seven, eight, nine years of life than most people have in 80 or 90 years.
“For him to have touched so many people and leave such a major legacy, that’s going to be a huge comfort going forward for us.”