The hosts raced into a two-goal lead early on, and despite Mani Dieseruvwe pulling one back, they reinstated that cushion before the break.
Casey Pettit netted another stunner in the second half but Dale couldn’t find another to take anything away from Roots Hall.
Despite the defeat, Jimmy McNulty’s men remain two points clear at the top of the Enterprise National League, with eight games remaining.
The Head Coach named an unchanged starting line-up from Saturday’s win at Eastleigh, whilst there was one change on the bench, as David Tutonda replaced the injured Bryant Bilongo.
Dale fell behind inside the opening three minutes, when a swift Southend move led to Andy Dallas slotting home the opener.
Strong Southend defending prevented an equaliser on a couple of occasions, before the hosts doubled their lead in the 17th minute, when James Golding turned home after a wide free-kick was sent into the area.
That initial two-goal lead lasted less than three minutes, with Dieservuwe netting his 24th league goal of the campaign. A ball was sprayed out to Dan Moss on the left, who chested down past his marker and squared into the area for Dieseruvwe to sweep home.
Ryan East was prevented from getting a shot away by a superb last-ditch tackle after a fine Dale move, just moments before Devante Rodney lashed a volley only inches over the crossbar.
However, the hosts restored their two-goal cushion in the 27th minute when the ball fell to Tom Hopper at close range, who made no mistake from a central position.
East and Dieservuwe sent efforts narrowly off target, and Kyron Gordon’s cross-shot was denied by Collin Andeng Ndi’s diving save to his right, as Dale looked to reduce the deficit once again before the break.
The hosts finished the half strongly, though, with Oliver Whatmuff holding Dallas’ strike and then making a stunning love save from James Morton’s deflected effort, turning it onto the upright.
Harry Boyes sent the final strike of the first period over, with Dallas hitting one wide after the break and seeing another well blocked by Gordon.
Pettit pulled one back in the 55th minute with his second in as many games. Gordon’s drive forward and low ball was cleared to him 20 yards out, and he curled a beauty into the far corner.
Half-time substitute Tyler Smith saw a shot blocked, and Dieseruvwe had an effort deflected wide, before Smith glanced a header onto the top of the crossbar from Allarakhia’s right-wing cross.
Dale continued to push forward in the closing stages, but even despite the introductions of Ian Henderson, Ed Francis and Connor McBride, they couldn’t create a clear-cut opportunity that would earn a late point.
Southend United XI | Andeng Ndi, Scott-Morriss © (66’ Coker), Dallas (66’ Kendall), Austin (88’ Goodliffe), Hopper (67’ Spasov), Gubbins, Taylor, Appiah-Forson (88’ Bridge), Morton, Golding, Boyes.
Unused subs | Walker, Mawene.
Scorers | 3’ Dallas, 17’ Golding, 27’ Hopper.
Dale XI | Whatmuff, Gordon, East, Ebanks-Landell ©, Allarakhia (88’ McBride, Dieseruvwe, Rodney (83’ Henderson), Pettit (83’ Francis), Barlow (46’ Smith), Moss, Perry.
Unused subs | Tutonda, Burger, Hosannah.
Scorers | 20’ Dieseruvwe, 55’ Pettit.
Attendance | 7,259 (170 away).
