Nailers endured a disastrous 90 minutes at the Marston’s Stadium in the Derbyshire Senior Cup on Tuesday night.
Player-manager Jon Froggatt rested key players such as Watt, Warne, Ross and indeed himself.
Gresley took the lead after 18 minutes when King played a low ball across the box where Mulonga slid in at the far left post, unmarked, to stab the ball home.
The visitors got their second goal after O’Connell latched on to a loose ball inside the box to drive the ball in from close range after 35 minutes.
Two minutes later Gresley made it three after O’Connell played a neat back-heel to Mulonga whose first time strike hit both posts before dropping in to the goal.
The second half proved a mirror image of the first, as Gresley struck three times.
The fourth goal of the game came on the 59th minute when Edwards beat Goulding to the ball on the right, before cutting inside and curling a left-footed effort into the far corner.
Soon it was five with 15 minutes remaining when Mulonga worked the ball into the box and played a square ball to O’Connell to tap in a simple goal.
The visitors scored their final goal of the night with four minutes remaining when Langston’s clinical finish from the edge of the box found it’s way in to the bottom left corner.
The Nailers produced little going forward, their closest efforts coming from a Burbeary header which was tipped away, and Pride’s long range strike hitting the top of the bar.
Belper Town: Martin, Jones (James 73), Varley, Towey, Goulding, Adams, Pride, Cotton, Burbeary, Holden, Stevenson. Subs: Warne, Froggatt, Ratcliffe.
Gresley FC: Townsend, Johns, Harrison, Carlisle, Barrett (Smyth 62), Grice (Graves 81), Mulonga, O’Connell, Edwards, Langston, King (Hanson 81). Subs: Peel, Binks.
Referee: James Thornhill (Ilkeston)