Sunderland led the sporting tributes to "inspirational" young fan Bradley Lowery, who died after a battle with a rare cancer.
The six-year-old struck up a close friendship with star striker Jermain Defoe after he was diagnosed with neuroblastoma.
In a statement on the family's Facebook page, Bradley's mother Gemma Lowery said: "My brave boy has went with the angels today 07/07/17 at 13:35, in mammy and daddies arms surrounded by his family.
"He was our little superhero and put the biggest fight up but he was needed else where.
"There are no words to describe how heart broken we are.
"Thank you everyone for all your support and kind words. Sleep tight baby boy and fly high with them angel."
Bradley was a mascot for Sunderland several times last season and found a place in the hearts of thousands of football fans around the world and the club extended their love to his parents Gemma and Carl and his brother Kieran.
"Despite battling neuroblastoma for much of his all too short life, he demonstrated a bravery and fortitude beyond his years that humbled us all," the club said in a statement.
"He had a special relationship with Jermain Defoe and their feelings for each other were evident for all to see. Jermain, naturally, is heartbroken."
Bradley and Defoe were pictured snuggled up together at the youngster's home in Blackhall, County Durham last week after the little boy had a party in bed as a way of saying goodbye.
Defoe broke down in tears on Thursday at a press conference with his new club, Bournemouth, when asked about their special bond.
Defoe's team-mate, goalkeeper Vito Mannone, who joined the Sunderland striker at Bradley's sixth birthday party in May, said his heart was broken.
The Italian told his Instagram followers: "I wished this day would never come. My heart is broken and I have no words but i want to remember your incredible smile and I am honoured that I met you and had the chance to spend fantastic moments with you little Bradley and your family."
Bradley's family also had close links with Everton after the Premier League club pledged B£200,000 towards his treatment when he was mascot for the match between Sunderland and the Toffees.
He went on to be a mascot for the Merseyside club too.
Chairman Bill Kenwright said: "One of football's all-time greats. We are so privileged to have known him...and will always be proud that he chose us as his second club.
"We send our loving thoughts to his mam and dad and his family...plus those who were inspired by him throughout the world of football. Bradley Lowery. There's only one Bradley Lowery."
