Deeping Rangers took the lead four times and eventually returned to winning ways thanks to Scott Mooney’s hat-trick.
In the second minute, David Burton-Jones’ free-kick was tipped onto the post and Mooney reacted quickest to put the home side ahead.
Harrowby were on level terms 10 minutes in with a solo effort from Scott Webb.
Deeping regained the lead after 21 minutes as Scott Coupland swept home Will Bird’s delivery from the right wing.
Harrowby equalised for a second time after 26 minutes as Fraser Bayliss scored at the second attempt after Daniel Bircham saved his initial effort.
Ten minutes before the break Rangers regained the lead again with Bird’s pass playing in Mooney to round goalkeeper Jonny Hotson and slot home.
The Arrows scored a third equaliser five minutes into the second period through Bayliss.
The key moment in the game arrived four minutes past the hour mark. Henry Dunn’s low 25-yard drive found the bottom right-hand corner of the Arrows net, only for the assistant to raise his flag for offside. The referee overruled him and the goal stood.
Ten minutes later Deeping had breathing space as Mooney evaded two challenges and steered a low shot under Hotson to complete his treble.
Harrowby’s woes mounted after 76 minutes when a swift counter-attack saw Mooney send Coupland clear, only to be brought down by Hotson who was red carded. Burton-Jones sent substitute keeper Nathan Jessop the wrong way from the spot.
Deeping made it seven with two minutes remaining as Coupland tapped home. In the final minute he was denied a hat-trick by the post.
Deeping: Bircham, Flack, Smith, Burton-Jones, Tinkler, Hunnings, Dunn, Avis (Lewis), Mooney, Coupland, Bird (Humphrey).
Deeping take on Premier Division leaders Leicester Nirvana on Saturday in their final home game of 2015.