Huddersfield remain in the Championship relegation zone with just two games left to play after suffering an extremely damaging 4-0 defeat at home to in-form Swansea.
Second-half goals from Jamal Lowe, Ronald, Jerry Yates and Liam Walsh secured a third consecutive win for the Swans, and leaves the Terriers in the bottom three.
Their penultimate game of the season sees them welcome Birmingham – the team directly above them in the league table – to the John Smith’s Stadium in what is likely to be a decisive encounter in the battle against the drop.
Swansea manager Luke Williams named an unchanged side from the recent home wins over Stoke and Rotherham.
And they came closest to opening the scoring in a fairly uneventful first-half, with Jay Fulton’s low driven shot in the 28th minute well saved by Lee Nicholls and put behind for a corner that came to nothing.
There was also a brilliant chance for team-mate Liam Cullen just before half-time, but he sent a free header wide from Josh Tymon’s cross.
Huddersfield, who were also unchanged from the team that started the 1-1 draw away at Bristol City last time out, registered a couple of attempts before the break but Josh Koroma and Jack Rudoni were able to hit the target.
Cullen again threatened to put the visitors ahead early in the second-half as his left-footed shot from the edge of the box clipped the right-hand post.
Down at the other end, Delano Burgzorg pounced on a loose back-pass from Ben Cabango and rounded onrushing goalkeeper Carl Rushworth, but his shot was blocked and Swansea managed to avert the danger.
Both sides made three substitutions shortly after the hour mark in an attempt to find the breakthrough.
And Huddersfield should have gone ahead in the 69th minute, when Koroma blazed his effort over the crossbar after the ball fell kindly for him inside the area.
It proved to be a very costly miss as four minutes later, Swansea substitute Lowe – who had been on the pitch for less than 10 minutes – found the bottom corner from the left of the box after latching onto Jamie Paterson’s pass.
The hosts thought they had equalised in the 80th minute as substitute Danny Ward’s effort hit the inside of the right-hand post and the ball flew straight back across the line and out for a goal kick.
They were punished again for their profligacy in the closing stages, with Brazilian Ronald finishing into an empty net after Tymon drove forward and laid it on for him perfectly.
Extra gloss was added by substitutes Yates and Walsh in stoppage time, with the former tapping in from close range and the latter looping a shot from distance beyond the reach of Nicholls.