In front of a crowd of 8,275, which is the Shrimpers’ biggest attendance of the season, Will Grigg turned in Michael Jacobs’ cross on 27 minutes to put the Spireites ahead.
But a crazy three minutes after the hour-mark saw them concede twice as Jack Bridge converted from the penalty spot before Wesley Fonguck’s deflected shot found the bottom corner.
This was just Town’s second defeat of the season and their first since August. But they remain top of the table by five points because Barnet lost at home to Gateshead. Had the Spireites won it would have been the first time since 1933 that they would have secured eight victories on the spin.
Paul Cook made two changes from the win against Barnet. Darren Oldaker and Jacobs came in for Mike Jones and Armando Dobra.
This game had been in doubt earlier in the week because of the three international call-ups for the Shrimpers but the National League ordered it to go ahead. Mauro Vilhete and Daniel Kanu were missing but Noor Husin opted not to join up with the Afghanistan squad due to an ongoing dispute and he started. Due to their off-field issues, which has left them with a threadbare squad, they could only name two substitutes on the bench.
The first-half was fairly even in terms of possession and there wasn’t a lot to choose between the two sides. Harry Tyrer was forced to make two saves, the first from Bridge was a good reaction stop, and another from Harry Cardwell was a decent parry. Cardwell also blasted a third attempt from a tight angle wide. Gus Scott-Morriss’ long throws into the box also tested Town’s back-line.
Down the other end, the Spireites had racked up five corners. From one of those, they played it short and Liam Mandeville’s low cross just needed a touch but nobody was there to turn it in. Chesterfield had been guilty of giving up possession a bit cheaply, which left Cook with his hands on his head at times, but they took the lead on 27 minutes. The Shrimpers claimed Ryan Colclough was offside in the build-up, but play went on and Jacobs delivered an inch-perfect cross from the right and Grigg applied the finish from close-range. Southend had the best defensive home record in the league going into this game - this was just the seventh time they had conceded at Roots Hall.
As the half went on, a Blues counter-attack led to Colclough testing Martin at his near post, and another attempt from the winger was straight down the throat of the home stopper. In the remaining minutes, Chesterfield had managed to prevent Southend from creating any other chances.
At the start of the second-half, Grigg worked the channel smartly before playing in Colclough, who fired into the side-netting. Not long after Martin blocked from Grigg at the near post.
Chesterfield were not in any danger on the hour-mark, but a couple of mad minutes saw them concede twice. First, Branden Horton clattered into Harry Taylor and referee Stephen Parkinson correctly pointed to the spot. Bridge converted down the middle to equalise.
Three minutes later, Southend went in front when a loose pass from Ash Palmer went straight to Fonguck, whose shot deflected in off Oldaker. Tyrer got hands on it and should have kept it out.
With 10 minutes to go, Chesterfield had two shots - one from Grigg which went over the bar - and a second from Naylor which Martin got down low to.
Southend would be in the play-offs had it not been for a 10-point deduction so this defeat is not as surprising as some might think. Despite their thin squad, their first 11 is very good and they are spirited. Six minutes were added, Grigg scooped over the bar late on, but Cook’s men could not force an equaliser
Chesterfield: Tyrer; Mandeville, Palmer, Grimes, Horton; Oldaker (Jones, 63), Naylor; Jacobs, Banks (Dobra, 63), Colclough (Berry, 87); Grigg.
Unused subs: Freckleton, Quigley.