The managerless Spireites slipped to a fifth straight league defeat for the first time since October 2011 as Danny Mayor pounced on an error to score the game’s only goal in the 68th minute.
In a game that was played in torrential rain, Drew Talbot headed a ball towards Sam Hird and the unpredictable nature of the pitch was partially responsible for the defender failing to bring the ball to heel.
In nipped formerSheffield Wednesday player Mayor. He still had plenty to do but his rapid burst towards the box gave him space and time and his precise shot across goal shattered the stalemate.
Mayor had been the outstanding man on the park. Chesterfield started with a 3-5-2 formation but were run ragged by the winger and his opposite flank man, Joe Dodoo.
Mayor picked up a stray pass, burst forward and hammered the post, as did Tom Soares from the rebound.
Soon afterwards, another Mayor run led to the deftest of chipped passes for Dodoo who volleyed against the upright.
The opening salvos from Bury led to Chesterfield interim boss Mark Smith changing things round.
He said: “It looked to me as though we needed to get to a back four as quickly as we could after they had a few chances that were a little bit too scary.
“So we went to the four and got to half-time and I put Jay O’Shea and Dan Gardner on. I was even thinking of doing that after half an hour.
“I felt we were defending too deep, allowing them to come on to us, and then we weren’t defending enough, allowing them to get crosses in.
“We also looked to have forgotten about attacking, but after switching to a four we looked a lot better.
“We needed to get further up the pitch in the second half and the changes worked a treat. The subs carried a threat going forward.”
The formation and personnel changes certainly worked.
Ahead of the break, a Sam Morsy long-ranger that stung the palms of keeper Daniel Bachmann was the Spireites’ best effort.
After it, O’Shea led the resurgent visitors, having failed to start a league game for the first time this season.
He shot inches over from distance, had another shot deflected over and generally caused issues for the left side of David Flitcroft’s defence.
It was his long ball in stoppage time that almost nicked a point for the visitors. Supplementary attacker Ian Evatt stretched to shoot from O’Shea’s feed only for Bachmann to move into overdrive to make the game’s best save with a full -ength, low dive to his left.
Smith added: “We went a bit route one at times but we were behind in the game and sometimes you have to do that, so we shoved Evo up front and it nearly paid off as the keeper made a good save.”
Regarding the weather, which had seen long pre-kick-off examinations from referee Peter Bankes, Smith commented: “It wasn’t the best of conditions but both teams were happy to play and it didn’t really get any worse even though the rain never stopped coming down.
“The referee was happy for it to start. It wasn’tsticking much and there weren’t any puddles.
“To be fair, the pitch looked very good and it played pretty well.”
The Spireites are back in action tomorrow night with an FA Cup replay at Walsall,with the winners set to visit Brentford in round three.
Lee Novak, missing at Bury with a calf injury, should be available, but Richard Wood remains sidelined and Ollie Banks is nursing a knock picked up at Gigg Lane.
Bury: Bachmann 6, Riley 6, Clarke 6, Cameron 7, Pugh 5, Mayor 9, Etuhu 6, Soares 7 (Brown 74), Dodoo 7 (Jones 59, 7), Rose 6, Pope 5 (Nardiello 67, 6). Subs not used: Lainton, Sedgwick, Dudley, Burgess.
Chesterfield: Lee 6, Evatt 6, Raglan 6, Hird 5, Talbot 7, O’Neil 6 (O’Shea H-T, 7), Morsy 6, Banks 7, Donohue 5 (Gardner H-T, 6) Dieseruvwe 5 (Simons 67, 5) Ebanks- Blake 7. Subs not used: Chapman, Ariyibi, Maguire, Humphreys.
Goals: Mayor 68.
Referee: Peter Bankes (Liverpool).
Attendance: 2,962 (287).