If you mean that Manchester City just moved into first place:
Urbs Mancunium locum primum capit.
Background: Manchester was founded by the ancient Romans in 79 A.D. They called it Mamucium or sometimes Mancunium. The latter seems to have won out. Vicipædia gives Mancunium Urbs for the name of the football team, but I think Urbs Mancunium follows Latin custom a little better (also used by Vicipædia here).
I didn't find clear-cut precedent for a Latin expression for "first place" in a contest or race, but I did find some where locus primus indicates the most prestigious position, so it seems right. Positionem primam is probably fine, too, as is tenet. Tenet is probably better if you just mean that Manchester City is in first place, not that they just got there.
If this is very big news and you want to go all-out Roman, either on stone or newsprint, you could make the headline:
If in doubt, you should take Tom Cotton's suggestion over mine. I'm just a little past the beginner stage and getting this from dictionaries and searches. Tom's got a genuine feel for the language from extensive use.