Chorley have it all to do if they are to reach the Vanarama National League North Play-Off final for the second time in three years.
A stunning second half strike from Arthur Gnahoua means Kidderminster will take a crucial one-goal advantage into Sunday’s second leg at Aggborough.
Roared on by another bumper Victory Park crowd of 2,487, Matt Jansen’s plucky Magpies gave everything but they failed to make home advantage count on a night when clearcut opportunities were scarce.
Ritchie Branagan, back in goal for the Magpies, was stretched to collect a dangerous right-wing cross at the second attempt and then Chorley had a real escape.
Following a corner, Jordan Tunnicliffe clipped a fine looping shot towards the top corner of the net, the ball beating Branagan but striking the bar.
The Magpies’ first serious goal threat came from Adam Blakeman whose well-struck low drive forced Sam Hornby into a scrambling diving save.
Jake Cottrell was everywhere chasing down possession for Chorley and they came more into the picture towards half-time.
An off-balance back header into the Kidderminster defence had Hornby struggling and the keeper was unable to prevent the ball going out for a Chorley corner.
The Magpies promptly forced a second one, defended by all 11 Harriers’ players.
Chorley improved considerably after the break and began to pose more of an attacking threat but the visitors proved difficult opponents.
The Magpies also had two major escapes when Branagan pulled off a reflex save with his legs from Joe Ironside and another effort came back off the post.
At the other end, substitute Adam Roscoe (above) appeared to have strong shouts for a penalty but the referee Marc Edwards was unmoved.
Then Gnahoua struck what could prove to be the decisive blow in the 77th minute when he brushed off Roscoe on the edge of the area and promptly hammered an unstoppable shot beyond the helpless Branagan.
Harriers successful ran down the clock in the closing stages but there was one last chance for Chorley when Dale Whitham blazed over from 12 yards.
Chorley: Branagan, Challoner, Jarvis (Beesley 82), Teague, Leather, Charnock (O’Keefe 82), Blakeman (Roscoe 60), Whitham, Carver, Walker, Cottrell.