Ballymena clinched a thumping win over Donegal Celtic, who remain in line for a potential promotion-relegation play-off at the end of the season.
Sean Cleary scored on two minutes after his initial penalty had been saved by United goalkeeper Dwayne Nelson.
Mark Burns turned a Gary Thompson cross into his own net after 10 minutes and Gary Liggett lobbed John Connolly with an opportunistic 30-yard effort on 19.
Shane Dolan grabbed the third and then Alan Teggart kept his cool to fire in.
Dolan found the net from a Cushley cross and Teggart added the fourth in the final minute.
The visitors lost skipper Allan Jenkins to injury late in the game.
DC are five points ahead of bottom club Lisburn Distillery.