Manchester United striker, Chido Obi-Martin on Saturday scored a hat-trick inside the opening 15 minutes of his full debut for the Red Devils’ Under-18 side. Obi-Martin is regarded as one of the best strikers in his age group. He emerged as a top talent at Arsenal having once scored 10 goals in a single game against Liverpool at Under-16 level. The 16-year-old joined Man United from Arsenal this summer. He made his first appearance for Man United’s Under-18 side last week, coming off the bench in a 4-3 win against Sunderland. But he was named in the starting XI on Saturday afternoon as he nett…