Wrexham were on top form as they followed the 4-0 win against Swansea on the weekend with an even better repeat performance.
Their two goals in three minutes near half time put the home side in the driving seat and the match was over as a contest long before Chris Curran was sent off for handball ten minutes from the end.
Wrexham's top scorer Andy Morrell claimed the match ball after completing his hat-trick to seal his spot as the side's leading scorer, with double the number he achieved in the whole of last season.
Wrexham manager Denis Smith said: "It was an extremely good performance against a side who are fancied to have a chance of winning the championship.
"Goalkeeper Andy Dibble had so little to do that I thought of taking him a box of cigars and an armchair."
Manager John Cornforth was amazed by their near surrender, he said: "I just can't believe what I've seen I don't think we strung two passes together in the game, so we can't do much worse. I have Welsh connections and my pride has been badly shattered."
He blamed keeper Kevin Miller for the first two goals and said they turned the game. On an unhappy note he added: "Unless results change very quickly my days as manager might be numbered."
Morrell headed home from Paul Barrett's left-wing free-kick then scored the second with a carbon copy header after Darren Ferguson picked him out at the back post with a free-kick from the opposite edge of the penalty area.
Ferguson robbed James Coppinger 20 yards out, ran a couple of steps and bent a shot into the top left corner to make City's task nearly impossible straight after half time.
Wrexham made and missed more chances before Curran was sent off for handling Morrell's shot to concede a penalty which the Wrexham striker converted for a hat-trick