Ali Al Habsi's horrendous first-half mistake allowed Silva to grab a winner for the hosts with his fifth goal of the season that allowed them to profit from Arsenal's failure to beat Sunderland and close to within four points of the Gunners.
City officials had not expected Kolo Toure to be in attendance to watch his team-mates in action. But Toure was there, although any enjoyment could surely only have been partial.
City gave up a half-time lead right after the re-start against Fulham on Sunday and nearly did exactly the same again. Antolin Alcaraz crept into space to meet Ben Watson's corner at the near post, flicking the ball over Pablo Zabaleta and onto the crossbar.
The home supporters were starting to sense a problem when McCarthy let fly with a fizzing half-volley from 25 yards that brought an excellent save out of Joe Hart. The Latics consistent failing this season though has been their inability to score, and this represented the 11th time this term they have failed to find the net.
Conor Sammon had one last chance of claiming the point Wigan deserved when he was sent through by Hugo Rodallega but his shot rolled agonisingly wide of the far post.