Kenny McLean's strike kept Hibernian firmly in relegation danger as Pat Fenlon's side fell 1-0 to 10-man St Mirren in Paisley.
McLean finished from the edge of the box midway through the second half and St Mirren survived Marc McAusland's 77th-minute red card without any major scares. Hibs, without top goalscorer Garry O'Connor, suffered another blow to their Clydesdale Bank Premier League survival hopes in injury-time when Lewis Stevenson was sent off.
Hibs remain just three points ahead of bottom club Dunfermline, who secured their first home win of the season 24 hours earlier against Aberdeen, and key midfielder Stevenson will now miss Wednesday's trip to Pittodrie.
Fenlon's men have lost both games without scoring since their William Hill Scottish Cup semi-final win over the Dons. He was frustrated over referee Stephen Finnie's failure to award a penalty for Dougie Imrie's challenge on Leigh Griffiths, but his side were short of creativity and width in particular.
The match started with both sides getting forward and Griffiths forced a near-post save from Craig Samson before team-mate George Francomb volleyed well over from 18 yards after the ball fell to him following a corner.
Saints were getting forward quickly through Paul McGowan and Nigel Hasselbaink and they created the best chance of the opening quarter when Steven Thompson headed Graham Carey's deep inswinging corner just wide.
St Mirren had a decent spell of pressure but they were almost caught out with a simple ball down the channel from Hibs right-back Matt Doherty. Eoin Doyle ran on to it unchallenged and lifted the ball over the onrushing Samson, but he could not direct it on target.
Hibs were made to pay for the missed chances in the 65th minute as Jeroen Tesselaar burst forward on to an instant and perfectly-weighted return pass from substitute Imrie before laying the ball inside to McLean to sidefoot just inside the far post from 18 yards.
Hibs, who had Roy O'Donovan on for Doyle, were given a lifeline when McAusland, who had been booked in the 36th minute for bringing down Isaiah Osbourne with a sliding challenge, was shown a second yellow card for pulling back Griffiths.
But the visitors failed to test Samson further, with a spectacular but wayward scissors kick from Griffiths summing up their desperation. Stevenson, booked earlier for a late tackle on Imrie, was then penalised for a challenge on McGowan to cap a frustrating afternoon for Hibs.