Connor Roberts' 87th-minute header earned Swansea a 1-0 win over Nottingham Forest and gave their automatic promotion push a major boost.
Chris Hughton's visitors were left kicking themselves as they had the game's best opportunities and the in-form Swans struggled to find their rhythm.
Anthony Knockaert was Forest's main threat, but the visitors paid the price for failing to convert and Wales full-back Roberts made them rue those missed chances late on.
Swansea had hammered Forest 5-1 when the two sides met in the FA Cup on January 23 and it was no surprise the home side had most of the early possession.
But it was far from a one-sided contest and Swansea's left wing-back Jake Bidwell escaped a card for diving in on James Garner. Forest's players screamed for a red, but not even a booking was given by the referee.
Steve Cooper's men were sloppy in possession and their passing tempo was not what their head coach would have wanted.
A wicked cross from the right from Knockaert nearly resulted in the opening goal, but Swansea's defence scrambled the ball away before Filip Krovinovic volleyed over.
Swansea's lethargy was summed up right on the half-time whistle when they failed to mark from a short corner. Forest played the ball to Knockaert who curled a shot off the crossbar.
Knockaert started the second half as he ended the first with another great chance, this time heading wide at the back post, before Joe Lolley had two shots saved from distance.
Forest's dominance continued and Lewis Grabban was the next to go close. The Forest captain fired wide from close range when he should have hit the target.
Cooper had seen enough and swapped defender Kyle Naughton – who left the field with a bloody nose – with Jordan Morris.
USA attacker Morris moved to the left wing as Swansea switched to a more attacking formation, but it made little difference.
Lewis Grabban butchered a fine chance when Forest caught Swansea on the counter.
Veteran striker Glenn Murray came on to replace Grabban and sniffed out an opening from a low Forest cross from the right, but there was no sign of improvement from Swansea until Roberts popped up with the only goal.
It came out of nowhere with Bidwell putting in a high cross from the left and his fellow wing-back Roberts rose highest to give Swansea's automatic promotion hopes a shot in the arm.
