James McFadden's goal from the penalty spot two minutes into first half stoppage time earned Blues a 1-0 win against Roberto Martinez's side and took them onto 40 points and an eighth placed position in the Premier League table.
"We're still in the stage of development so to get to 40 points before March is an outstanding feat from a squad that cost £10m in the summer to assemble," ," the Blues boss told Sky Sports after the game.
"That is amazing and it is even more amazing that we are in eighth position but we now want to kick on and the characters in the dressing room will ensure we don't ease up.
"We've played a lot better than we did today.
It was a bit fraught and anxious in the second half and Wigan threw caution to the wind but once again Joe Hart made a couple of fine saves to earn us the extra two points."