The Inishown side beat Swilly Rovers 7-1 at Maginn Park on Sunday to move seven points clear of seconded placed Derry City.
Garvan Friel scored a hat trick while Conor Carlin and Derek Doherty bagged two goals each.
With only a few games left to play Derry City must win their game in hand on Wednesday night to keep chase with Cockhill.
The Candystrips play Finn Harps also at Maginn Park.
In the other games yesterday Drumkeen United beat Finn Harps 2 nil while Bonagee Utd came from 2 nil down to force a 2 all draw in the derby with Letterkenny Rovers.