See the best images from Blues' 4-0 win over Gillingham...
Three goals in 11 minutes for Blues set Southend on course for their first win against Gillingham in 10 attempts as Michael Turner opened the scoring with a textbook header after just eight minutes.
Theo Robinson then marked his first league start since October with a close-range volley before Michael Kightly nodded in on the rebound after Stephen McLaughlin had rattled the crossbar.
Southend grabbed a fourth before the interval as McLaughlin headed in from a Kightly corner before Gills captain Lee Martin was shown a straight red card for a late challenge on Robinson.
It was the first time Blues had scored four in the first-half of a game since 2011 against Macclesfield Town and it was more than enough to end their six-year wait for a win against their local rivals.
The victory maintained Southend’s place inside to top half of the League One table ahead of a trip to Blackburn Rovers on Saturday while Gillingham slipped to 15th.
It was such a contrast in emotions at Roots Hall compared to the disappointment felt after Blues lost by the same scoreline just four days previously against a rampant Plymouth Argyle side.
In fact, both sides came into Monday’s local derby off the back of defeats with Southend’s humbling at Plymouth on Good Friday following Gillingham’s 2-1 reversal at home to struggling MK Dons.
Off the back of that defeat to Argyle, Chris Powell made three changes to his Blues side with Michael Timlin, Michael Kightly and Theo Robinson coming in and within 18 minutes of the kick-off, two of those three were on the scoresheet in a lighting start for Blues.