Hibernian old boy Dean Shiels ensured the Scottish Cup finalists' battle to avoid Clydesdale Bank Premier League relegation continues after Kilmarnock claimed a narrow 1-0 victory at Easter Road.
Hibs were dominant for long periods but it was Scottish Communities League Cup winners Killie who emerged victorious as Shiels converted a 44th-minute penalty against the run of play after Jorge Claros was adjudged to have brought down Liam Kelly.
Leigh Griffiths, who scored the William Hill Scottish Cup semi-final winner to set up next month's all-Edinburgh final, was lively for Hibs, but Pat Fenlon's side now hold a six-point advantage over bottom club Dunfermline with four games to play.
The win saw Killie return to seventh place above Aberdeen and meant Hibs have one win and 10 losses at home this term and may yet require victory over Dunfermline on May 7 to avoid the drop.
A cross from Ivan Sproule was just too far in front of Isaiah Osbourne and Cameron Bell collected before Griffiths, who appeared full of confidence after scoring the winner against Aberdeen last weekend, attempted to go by Michael Nelson on the edge of the area but went to ground and was booked for diving by referee Craig Thomson.
Griffiths was allowed space to shoot from 25 yards and forced Bell to turn the ball over the bar before an O'Connor header from a corner hit team-mate James McPake inside the six-yard box and the visitors scrambled clear.
McPake headed a Lewis Stevenson cross narrowly wide and Bell had to head clear after Griffiths attempted to latch on to a high ball forward from Claros, who then conceded a penalty.
Kelly was tripped in the box and Thomson had no hesitation in pointing to the spot, with Shiels converting to give the visitors the half-time lead against the run of play.
An acrobatic Roy O'Donovan effort was blocked before James Dayton mis-hit a clearance from a corner on to his own arm inside the area and the ball fell for Claros, whose effort was narrowly off target.
Substitute David Silva had an effort blocked by Matt Doherty after being played in by Shiels as Killie missed the chance for a second.