Southend moved up to fourth position in League Two with a win over Rochdale, who dropped out of the play-off places.
Dale went ahead when on-loan striker Terry Gornell headed his first goal for the club from a Phil Edwards cross.
But the Shrimpers responded quickly, with Britt Assombalonga firing in from 18 yards to level the scores.
Gavin Tomlin put the hosts in front after Josh Lillis could only parry Michael Timlin's cross, before Marc Laird chipped Lillis to seal the win.
VIEW FROM THE DRESSING ROOM
Southend United manager Paul Sturrock told BBC Essex:
"I was worried about the freshness of them after us playing Tuesday night, but we got stronger as the game went on.
"I didn't put a sub on, it was different class to see the boys running as hard in the 90th minute as the first. They've rolled their sleeves up and they deserved it in the end.
"Their work-rate, their attitude, everything was fantastic.
"Now we've got a settled side, they've played three or four games together, they all know what we are looking for. The system seems to be ideal for the players we've got."