Barnet remain bottom of League Two after picking up just one point from their latest two games.
Joe Devera popped up with a stoppage-time equaliser at Cheltenham Town on Saturday, the Bees drawing 1-1, but they could not follow up that good performance on Tuesday night.
Hosts Southend United were 2-1 victors, beating Barnet for a third time this season (twice in the league and once in the JP Trophy).
Steve Kabba netted a late consolation for the visitors at Roots Hall, but early goals from Craig Easton and Ryan Hall had already done too much damage.
Though the Bees hit the woodwork twice (through Glen Southam and Sam Deering), Southend were reasonably comfortable until Kabba's 88th-minute goal set up a tense finale for the Shrimpers.
But it proved to be too little, too late for Paul Fairclough's side.
Now Barnet are preparing for another important home clash this Saturday.
Mid-table Lincoln City are the visitors and it is a game the Bees really must win.
Barnet have played more games than their rivals, so time is running out.
The Bees are not playing that badly and Fairclough believed his team should have won the match at Cheltenham.
Sadly, defensive errors proved costly, both against the Robins and then at Southend.
Fairclough said: "It has been the story of our season. We're not getting any luck at the moment."
Lincoln will be no pushovers either. The Imps have hauled themselves well clear of the drop zone in recent weeks.
Kick-off at Underhill is 3pm.
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