Goals from Jay O'Shea and Marc Richards meant Bury's first match back in League Two ended in defeat by Chesterfield.
The relegated Shakers, playing under their new owners for the first time, fielded seven debutants and should have been ahead when Tom Soares failed to score from Shaun Harrad's cross.
And they were made to pay when O'Shea smashed home into the far corner.
As the hosts sought an equaliser, Richards grabbed the Spireites' second, finishing a well-worked counter-attack.
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Chesterfield first team coach Kevin Lynch told BBC Radio Sheffield:
"I thought it was a outstanding team performance, they are a tough team and set up well.
"Overall once we got the grip on the game, we showed the quality we've got.
"These first games of the season are always frantic, a bit fast-paced and we had to be patient.
"Jay O'Shea got his reward today for all of the hard work he put in over the summer."