Debutant Caolan Lavery's freak goal kept Chesterfield firmly in the Sky Bet League One play-off race as they secured a 1-0 win to heap more Meadow Lane misery on Notts County.In a frenetic derby both sides traded first-half chances, only the quality of County goalkeeper Roy Carroll and opposite number Tommy Lee keeping the game goalless at the interval.Lee in particular did brilliantly to keep out an effort from Balint Bajner, while Carroll also produced a wonderful stop to thwart Sheffield Wednesday loanee Lavery.Both sides continued to attack in the second half, but for all of the quality on show it was a freak goal which settled the contest.Attempting to deal with a long punt forward, County centre-back Haydn Hollis only managed to cannon his clearance against Lavery with the ball then sailing over the helpless Carroll.Notts threw on Kwame Thomas and Garry Thompson in an attempt to salvage an equaliser but their efforts were in vain, leaving County with just one league win at home in their last seven games.