Teenager Tammy Abraham bagged his first Premier League goal as Swansea sealed a vital first top-flight victory of the campaign.
But it was a horrible afternoon for pointless and below-par Crystal Palace – and in particular first-half substitute Martin Kelly.
Kelly came on when James Tomkins managed to injure himself shooting wildly over from 25 yards after 41 minutes.
And in the space of seven minutes either side of the break Kelly let striker Abraham, 19, run clear for a smart volleyed finish from the 19-year-old on loan from Chelsea.
Defender Kelly then gave away possession to Kyle Naughton to tee up Jordan Ayew three minutes after half-time.
Both are set to be busy this week in the transfer market, but it was the Eagles who appeared in greater need of reinforcements – with Liverpool’s Mamadou Sakho looking just one priority.
In a short spell of pressure from Palace James McArthur first headed wide, and then shot off target from 20 yards.
Abraham almost outwitted Timothy Fosu-Mensah forcing Wayne Hennessey into a save, and then Tomkins injured himself with a shot blazed over and had to be replaced.
Then before the break Abraham got ahead of sub Kelly and applied a clinical finish on the volley to Leroy Fer’s delivery.
And within two minutes of the second half Swansea had doubled their lead after a comedy of errors from the Palace defence, Ayew eventually scoring after a ricochet off Hennessey.
Palace toiled away - but it was to be a second straight disappointing home league defeat, and boos rang out at the final whistle.
You can follow all the drama as it happened from the Selhurst Park in our live blog below.
Plus, click here to keep track of the Premier League table as it stands.
Celebrations
Two very happy Swansea players there.
Both netted earlier in the week against MK Don and have repeated the feat against Crystal Palace.
Chelsea will be smiling to themselves at the talent of Abraham.
GOOAAAL! Crystal Palace 0-2 Swansea (Ayew)
Jordan Ayew scores his first Premier League goal for Swansea.
GOOAAAL! Crystal Palace 0-1 Swansea (Abraham)
Tammy Abraham netted his first goal for Swansea in the Carabao Cup in the week.
And now has his first Premier League strike.
The Chelsea loanee scored bags for Bristol City in the Championship last season.
Welcome
Sam Clucas could go straight into the Swansea side at Crystal Palace following his £15million move from Hull.
Skipper Leon Britton is also available after a back injury forced him out of the last two games against Manchester United and MK Dons.
But Kyle Bartley (knee ligaments) has joined a casualty list which includes Fernando Llorente (arm), Nathan Dyer (Achilles) and Ki Sung-yueng (knee).
Ruben Loftus-Cheek will miss Crystal Palace’s Premier League clash with Swansea at Selhurst Park.
The on-loan Chelsea midfielder has suffered a groin injury and joins winger Wilfried Zaha (knee) on the sidelines.
Midfielder James McArthur is pushing for his first league start of the season after scoring twice in the Carabao Cup victory over Ipswich in midweek.
Palace squad: Hennessey, Speroni, Ward, Tomkins, Dann, Riedewald, Fosu-Mensah, Van Aanholt, Delaney, Kelly, Schlupp, Townsend, McArthur, Cabaye, Milivojevic, Lee, Williams, Mutch, Kaikai, Puncheon, Benteke, Ladapo.
Swansea squad: Fabianski, Naughton, Fernandez, Mawson, Olsson, Britton, Fer, Carroll, Clucas, Ayew, Abraham, Nordfeldt, Rangel, Van der Hoorn, Mesa, Fulton, Narsingh, Routledge, Montero, McBurnie.