Mistakes at the back cost the Lynn dear as their eager visitors lapped up the late Christmas presents on offer.
All four of the visitors' goals cane as a result of shoddy home play and it means Lynn have now conceded 20 goals in their last six matches.
But things looked so good after ten minutes. when Lee Hudson put the hosts ahead. Hudson, who had earlier missed a glorious chance from six yards, latched on to a Steve Williams pass and guided his shot under the keeper.
But a mistake by skipper Colin Hoyle let in Atherstone for the equaliser. on 33 minutes. He should have cleared a high ball but managed only a weak header which Ashley Warner. picked up. He fed Richard Judd, whose drive beat Steve Lewis.
Defender Kevin Ellis limped off four minutes into the second half and was replaced by striker Julian Delicata. Hudson was switched wide as Lynn reverted to a 4-4-2 formation.
Only a minute later, Atherstone took the lead when Lee Middleton's corner was dropped into the back of his own net by Lewis. The visitors made it 3-1 two minutes later, Judd's looping header beating Lewis, who got a hand to the ball but could
not stop it going in. Atherstone then missed two good chances to increase their lead.
Home fans appealed for a penalty when Hudson a appeared to he tripped in up the box but nothing was given before Judd completed his hat-trick on 82 minutes catching the defence square and tucking the ball home.
Lynn: Lewis, Matthews, Wright, Hoyle, Ellis (Delicata 49), Pascoe, Hopkins, Mead, Williams, Stock, Hudson. Subs (not used) Roberts, Suiter.
Atherstone: Williams, Young (Barrett 45), Martin, Hart, Olner, Redgate, Judd, Middleton, Warner, Green (Ellison 80), Dean (Blair 45).