Peterborough United’s second half blitz condemned Blues to a 4-0 defeat at the Weston Homes Stadium with goals from Siriki Dembele, Jack Taylor and a brace from Ivan Toney.
Southend would hold their own in the first half and restricted Peterborough to just the one clear chance for Toney, while Matt Rush had a couple of half-chances come and go.
The visitors struck the woodwork after the break with Mark Milligan’s deflected effort coming off the inside of Christy Pym’s post, mere seconds before the home side would open the scoring.
Dembele would break the deadlock after being teed up by Joe Ward, sliding his shot through Oxley and in before Taylor would thunder one through a crowd a few minutes later to double the lead.
Toney then grabbed his 22nd and 23rd league goal of the season by rounding Oxley to slide home before looping a header into the net from a corner kick to round off the scoring.
Blues were always likely to be up against it this evening against a Peterborough side that had won their last five in a row and were chasing for automatic promotion to the Championship.