New Huddersfield boss Lee Clark was in the stands at Roots Hall to see them get their fifth victory in six games.
Ian Craney scored the winner after 49 minutes when he steered Michael Collins' cross past Southend keeper Steve Mildenhall from four yards.
Southend should have drawn level from the spot eight minutes from the end after Kevin Betsy was brought down by Robbie Williams.
But substitute James Walker's penalty was poor and Alex Smithies saved.
Cannot play media. Sorry, this media is not available in your territory.
Booked: Milsom, McCormack.
Please turn on JavaScript. Media requires JavaScript to play.
Booked: Craney, Goodwin.
Goals: Craney 48.
Att: 8,382
Ref: David Phillips (West Sussex).
What are these?
Print Sponsor
Bookmark with:
What are these?