Former City midfielder Adam Walker, who came through the City Academy and Reserve ranks and played a couple of first team games before he was released, opened the scoring in the 21st minute with former City Reserve team Mark Noon, who is a coach at City's Academy adding a second in the 42nd minute.
Metham pulled one back in the 59th minute but Nuneaton, who gave Cryus Christie a ten minute run out, took the away win which sends them to the top of the Conference North table.
Former City youngster Joel Grandison scored for Solihull Moors in a 2-2 home draw with Droylesden whilst Ben Mackey was on target for Corby in a 3-2 defeat at Vauxhall Motors.
Bedworth United won 1-0 at Hednesford Town in a Birmingham Senior Cup Second Round tie. Dean scored the only goal of the game in the 22nd minute.