Chesterfield fell to a 2-0 Boxing Day defeat as their lean losing run stretched to seven games, Conor Washington striking twice for Peterborough United at London Road.Goals either side of the break for Washington saw Peterborough claim a three points they deserved despite the doggedness of the Spireites' defensive performance.
With new manager Danny Wilson in the stands watching his side before he takes over on the touchline on Monday, caretaker Mark Smith handed out a debut to Derek Daly at left-back, the 18-year-old who has impressed in the youth team this season.
Starting with a 4-1-4-1 formation, the Spireites came within the width of the bar of an early concession when an overhit Posh cross was also over Tommy Lee, but bounced back into play off the woodwork.
Souleymane Coulibaly twice went close wriggling into the box and shooting low, but one effort was off target while the ther was easy for Lee to save.
Sylvan Ebanks-Blake went closest for the Spireites in the first 25 minutes as he chested down a lovely Jay O'Shea ball and hit a volley into the ground that Ben Alnwick was able to get his body behind to save.
However, it was Posh pushing and after Ollie Banks had mis-hit a shot that was comfortable for the Posh 'keeper, Washington tracked down a long ball, came inside but fired wide from inside the area.
With seven minutes to go before the break, United came close again and Lee had to be sharp and strong to keep Washington's poked effort out with his left arm.
Spireites were creating chances themselves and when Dion Donohue - reverting to left-back in an early switch with Daly - crossed from the wing with Banks very nearly prodding home from six yards.
Just as it looked as though the Spireites would get to the break level, they conceded a poor defensive goal when Marcus Maddison crossed and Washington was unmarked six yards from goal and headed home.
Lee was forced into another good save in the opening moments of the second half when Erhun Oztumer struck with power from 25 yards, the Spireites 'keeper equal to it and pushing round his post.
Smith has made two changes for the Spireites at the break, Richard Wood and Lee Novak coming in as the away side switched a 3-5-2 formation.
Livewire Coulibaly again went close as his sublime touch was soon smashed in but just over Lee's bar.
Ten minutes into the half and the Spireites had a huge shout for their first penalty of the season. O'Shea skipped past one man, rounded a second in the area and was felled uncerimoniously, but with nothing given to the luckless visitors.
After Coulibaly had another effort deflect into Lee's gloves Ebanks-Blake attempted to turn quickly in the other penalty area but lost the ball before he could get the strike in.
Despite the Spireites' best efforts Washington netted his and his side's second of the game on 76 minutes as he burst through and shot with power past Lee.
The game moving out of the visitors' reach the huff and puff of the Spireites' play was creating few chances, and Lee had to stretch fully in added time to keep out substitute Martin Samuelsen late on, the Spireites slumping to a seventh successive league defeat ahead of Wilson arrival on the touchline on Monday.
Peterborough United: Alnwick (gk) - Smith, Taylor, Bostwick, Oztumer (Samuelsen 70'), Maddison, Santos, Washington, Beautyman (Baldwin 80'), Coulibaly (Angol 70'), Forrester
Subs not used: Henry (gk), Fox, Addison, Nicholson
Chesterfield: Lee (gk) - Daly (Novak 46'), Raglan (Wood 46'), Evatt (c), O'Neil - Hird, Gardner (Simons 66'), O'Shea, Banks, Donohue - Ebanks-Blake
Subs: Cairns (gk), Dieseruvwe, Ariyibi, Herd
Peterborough United: Washington 45' 76'
Attendance: 7,153 (526 away fans)