What looked like being a comfortable home win turned into a real nail-biter as Spireites saw a 3-0 lead cut to 3-2 as Peterborough United fought back.
But the hosts did just enough to hold on.
Eoin Doyle turned in his 20th goal of the season after ten minutes, latching on to a low ball into the area from right back Tendayi Darikwa. That goal made the Irishman the fastest Spireite to reach 20 goals in a season since Jimmy Cookson in 1926. Cookson hit a record 44 goals for the club that season.
Fellow striker Armand Gnanduillet netted from eight yards after Doyle crossed for him on 34 minutes, then Doyle hammered home from just outside the box on 54 to give Paul Cook’s side a deserved and clear lead. The second strike was Doyle’s 30th goal of a magnificent 2014, which is sure to see frenzied interest in the January transfer window.
Gary Roberts skied a sitter that would have put the game beyond doubt but his six yard shot flew into the crowd.
Darren Ferguson’s Posh, second best at every moment in the opening hour, then saw defender Michael Bostwick head home sub Marcus Maddison’s free-kick before Maddison himself drilled in from the left and Luke James did enough to put off keeper Tommy Lee, whose appearance sees him move to No.2 in the club’s all-time goalkeeper’s list, and the complexion of the game changed completely.
Chesterfield held on, surviving a real 94th minute scare when Maddison burst through but Charlie Raglan and Lee did enough to shut him out as Spireites leapfrogged their opponents in the table.
n Chesterfield: Lee 6; Darikwa 7, Evatt 6, Raglan 6, Clucas 7; Boco 7 (O’Shea 72), Hird 6, Humphreys 6, Roberts 8 (Banks 72); Gnanduillet 7 (Jones 60, 6), Doyle 8.
n Peterborough: Alnwick 6, Bostwick 6, Burgess 6, Zakuani 5, Smith 7 (Mendez-Laing 72), Payne 5 (Maddison 28, 8), Newell 7, Oztumer 7, Beautyman 7, James 6, McLean 5 (Washington 60, 6).