Bible student Kwame Asare, 17, proudly posed for a snap as he met his Manchester United idol.He was the SEVENTH stabbing victim in South London in seven days, but the only one to die.A shattered relative said: "Kwame captained his school team. He made up his mind to play football. Rio told him to keep focus."The lad was walking to a relative's house with a pal when two thugs ambushed them in Brixton.Kwame, who posted his photo with Rio on his Facebook page, died in a pool of blood as the attackers fled across roofs.A horrified local said: "He was groaning, lying face down with blood coming from his side."Yesterday the youngster's distraught family, originally from Ghana, prayed for him at the Baptist church he attended.Cops fearing gang war drafted in reinforcements.One relative said: "Kwame was a good boy in the wrong place at the wrong time."