Freddy Eastwood's early goal gave Southend victory at Hartlepool, despite playing the second half with 10 men.
Will Atkinson seized on Darren Holden's poor clearance five minutes in, giving Eastwood an easy close-range finish.
The home side almost levelled when James Poole saw his shot finger-tipped wide, before Shrimpers striker Barry Corr saw red right on half-time after he fouled Jack Baldwin from behind.
But Southend resisted, limiting Pools to speculative shots from distance.
VIEW FROM THE DRESSING ROOM
Southend United manager Phil Brown told BBC Essex:
"I think it's marker down with the regards to the style of football we're trying to play, the work-rate, the mentality, the commitment, the togetherness. All of the things that managers really want.
"There was a lot of team spirit out there, defending and helping each other.
"I thought it was magnificent in terms of performance, and in terms of resilience and results.
"We had to be about our game, and when we went down to 10-men, it was going to be a real test of character and fitness and we showed it."