Anthony Malbon scored twice as Kidderminster secured a vital 3-1 win at fellow title chasers Grimsby.
Grimsby striker Ross Hannah's header was well saved by Daniel Lewis early on but it was the visitors, unbeaten in six, who took the lead.
Malbon lost his marker before applying a clinical side-footed finish to Mickey Demetriou's cross after 32 minutes.
The Harriers broke away on the stroke of half-time to double their advantage as Michael Gash tucked away Lee Vaughan's pull back to grab his first goal since arriving from Cambridge on loan.
The Mariners came back into the game five minutes after the interval when defender Ian Miller showed a striker's instinct to find the top corner with a right-footed strike.
But Steve Burr's side wrapped up the points in the 77th minute when Malbon tapped in substitute Danny Pilkington's centre.