Goals from Adam Barrett and Noel Hunt secured Southend their first victory of the season as they brushed aside Peterborough 2-1 at Roots Hall.
The Shrimpers wasted a glorious chance to take the lead when David Mooney headed John White's right-wing cross over the bar from six yards.
But it was not to prove costly as Barrett fired them in front in the 32nd minute, poking a shot home from close range after Hunt had been denied by goalkeeper Ben Alnwick.
After the break, Peterborough's Michael Bostwick fired against the crossbar and Jack Collison had an effort cleared off the line by Ben Coker.
In reply, Hunt was denied by Alnwick from six yards before he worked his way onto the scoresheet in the 70th minute.
The striker was picked out by an excellent right-wing free-kick from Coker and guided an accurate header into the bottom left-hand corner for his second goal in two games.
Peterborough hit back to net a late consolation with Marcus Maddison scoring but the visitors have now not won in six games.