MANCHESTER, England, Jan 17 : Manchester United re-ignited their season with an exhilarating 2-0 derby day victory over Manchester City whose Premier League title hopes suffered a devastating blow on Saturday. Former player Michael Carrick's return for a second stint as interim manager could hardly have gone better as United lifted the gloom over Old Trafford with a deserved victory. Goals by Bryan Mbeumo and Patrick Dorgu after the break rewarded a dominant display by the hosts who moved