Leaders Chesterfield saw their 13-match unbeaten run in the National League come to an end after a 2-1 defeat at Southend.
The Spireites, who had won 12 times during that streak, including the last five, opened the scoring in the 27th minute through striker Will Grigg.
The 32-year-old former Northern Ireland international took his tally to five goals in four league games when pouncing from close range from a Michael Jacobs cross.
But two goals inside three second-half minutes turned the game on its head as Jack Bridge levelled from the penalty spot on the hour after Harry Taylor was fouled by Branden Horton.
Chesterfield goalkeeper Harry Tyrer, who earlier made a fantastic save to keep out Bridge's volley, then allowed Wes Fonguck's cross, which took a deflection off Darren Oldaker, to slip underneath him.
Match report supplied by PA Media.