Dundee slumped to their third straight Ladbrokes Premiership defeat as Hearts piled more misery on them at Dens Park with a 1-0 victory.
After back-to-back defeats against Hibs and Rangers, Jim McIntyre's Dark Blues were determined to stop the rot only to shoot themselves in the foot by gifting Sean Clare a decisive 15th-minute winner for Craig Levein's men.
Now the toiling Taysiders, who remain just one point above bottom-club St Mirren, could go back to the foot of the table should Saints beat Kilmarnock on Monday night.
McIntyre's men must now lift themselves for next Sunday's visit of champions Celtic in their battle against relegation.
Dundee were looking to emulate their 2-1 win at Tynecastle in January, while their opponents arrived on Tayside in the wake of a lacklustre 1-1 Scottish Cup quarter-final draw with Championship side Partick Thistle earlier in the week.
The hosts were without former Sunderland striker Andrew Nelson who had hit the winner in Edinburgh on their return to Premiership duty due to a heel injury.
Their bright start, with Kenny Miller looking lively in attack, counted for nothing though as Hearts took an early lead.
Dundee's defence failed to clear and left Clare with the simple task of poking the ball through the legs of Seny Dieng from just a few yards.
It was a comedy of errors from the home team, although Kenny Miller did see his 17th minute low shot saved by Zdenek Zlamal.
At the other end, Callumn Morrison threatened to increase the visitors' lead and his 25-yard effort was just tipped away by Dieng to safety.
Dundee pressed as much as the could after the break in their pursuit of an equaliser.
Full-back Nathan Ralph was making a habit of getting down the left and this time his cross deserved better as nobody was quick enough to react and get a shot away.
Hearts made their first change after 66 minutes when former Dundee forward Craig Wighton replaced David Vanecek.
Soon after, Peter Haring forced the ball forward into the path of Uche Ikpeazu whose low effort was gathered by Dieng.
With 10 minutes left, goalscorer Clare surged down the left and his cross was turned behind by Ralph for a corner as Hearts tried to play out time, before Zlamal produced a stunning save to defy Miller's 84th-minute header.
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