The 22-year-old singer was driving past a school in Highgate, North London ahead of his concert when he decided to join few boys, who were in the middle of a soccer game, reported AceShowbiz.
"Justin and his manager came over to speak with us - I recognized him straight away. They had been driving past and seen our lesson going on," the school teacher, Mario Noto said.
"They explained Justin was in town for his shows at the O2, that he enjoys his football, and would love to join in. We thought this would be a great experience for the pupils.