Francis Breen, 59, fell to the ground clutching his chest after suffering a suspected heart attack at the Mighty Athletes game in Southampton.
Onlookers fought to save the much loved coach, with one parent giving him CPR.
Mr Breen had helped set up the Mighty Athletes under-nines side last year in a bid to get underprivileged children into sport.
His devastated son Jonathan, 23, told the said: "He died doing something he loved."
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