Chesterfield showed the fighting spirit they will need to escape relegation by casting serious question marks over Wrexham's play-off aspirations following a 2-1 victory at Saltergate.
The Welsh side were punished for some poor defending as second half goals from Steve Blatherwick and Ian Evatt saw Chesterfield recover from last week's 7-0 hammering at Plymouth.
A first league goal in Wrexham colours by Chris Armstrong gave the visitors a glimpse of a point but once again they caved in at the back.
Manager Denis Smith will certainly be concerned at how easily his team squandered possession and allowed Chesterfield too much space inside the penalty area.
On this showing, Wrexham will do well to stay in the chasing pack at the top of the division and Chesterfield certainly did not look a team so far behind their opponents in the league.
The tireless work of their midfield denied Wrexham time on the ball and constantly put pressure on the three central defenders who always looked uncertain.
Paul Edwards made a great saving tackle when Glynn Hurst was through on goal in the 16th minute but after that he gave the ball away time and time again.
Chesterfield had chances before the break but failed to take them and Chris Brandon wasted another clear chance when he headed right at the keeper from six yards.
When the goal came, it was from an unlikely source with Steve Blatherwick looping a header over Andy Dibble after Brian Carey appeared to slip.
The introduction of Armstrong paid off within five minutes of him replacing Paul Barrett when a free-kick from Darren Ferguson caused panic in the home defence.
Ferguson's ball into the six-yard area was met by Chris Llewellyn but Carl Muggleton made a brilliant save but the rebound dropped to Armstrong, who drove the ball into the roof of the net.
Chesterfield were also indebted to a sub, Leeds' on-loan striker Jamie McMaster for setting up the winning goal four minutes from the end.
McMaster headed into the path of Evatt and his strike from 12 yards flew into the bottom right-hand corner.