Jason Scotland spared Swansea's blushes as his late penalty was enough to see off battling Plymouth Argyle 1-0 in Tuesday's Championship clash.
The result moved Roberto Martinez's side back into the play-off places while Argyle now lie 18th, four points above the drop zone.
The home side dominated for huge swathes at the Liberty Stadium however it was left to Scotland to smash home a 78th-minute penalty following keeper Romain Larrieu's foul on Jordi Gomez to earn them three vital points.
Swansea came closest to taking the lead in the first half when Gomez drew a foul from Karl Duguid on the edge of the area and sent the resulting free-kick rattling against the bar.
Larrieu saved superbly from another Gomez set-piece after the break but the Spaniard was later fouled by the Frenchman in the box and Scotland scored from the spot to win it.