Match ends, Swansea City 0, Crystal Palace 1.
Alexander Sorloth's first goal for Crystal Palace sent them through to the third round of the Carabao Cup at Swansea City's expense.
The Norway striker turned his marker to shoot past Kristoffer Nordfeldt deep into the second half.
But the Sweden goalkeeper saved well from Max Meyer and Sullay Kaikai as Palace dominated the latter stages.
A youthful Swansea side had the better of long spells but failed to really test Palace keeper Vicente Guaita.
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Some 21 months after Swansea's thrilling 5-4 win against Palace at the Liberty Stadium, this was a much lower key event.
A game of few clear-cut chances, the best of which fell to the visitors, never truly got going until late in the second half when Palace took control.
But Swans manager Graham Potter will take some positives from the performances of the youngsters, particularly Daniel James and Yan Dhanda, who made the Palace defence work hard for their win.
Former Liverpool player Dhanda came closest to a goal in the first half, picking up Sorloth's loose pass in Palace territory and forcing a good save from Guaita.
The Premier League outfit struggled to get a foot in the game for the first hour but grew into the contest as the game progressed, and for all Swansea's good work it was the visitors who eventually opened the scoring.
Sorloth's nice turn eight yards from goal gave him the space needed to fire the ball past Nordfeldt and net his first goal for the Eagles.
Meyer almost doubled the visitors lead in the 78th minute with a 25-yard driving effort, but Nordfeldt got two strong gloves to parry the ball to safety before producing an even better stop from close range to deny substitute Kaikai.
Swansea now turn their attention to a trip to Millwall in the Championship on Saturday, while Palace will find out their third-round opponents on Thursday before hosting Southampton in the Premier League.
Swansea manager Graham Potter said: "The players did themselves and the club proud, conducted themselves well, gave everything, had courage and quality.
"You could see they tired a bit at the end, which is to be expected. It's the first game for a while for a few of them.
"Throughout we created some chances, we had some good play, we were brave on the ball and defended well."
Crystal Palace manager Roy Hodgson said: "It was a good game. The first half Swansea were very good, they got around the ball well and were sharp and quick.
"It took us a while to get our game together, we kept coming too deep to receive the ball.
"Towards the end of the first half we got (Jonathan) Williams and (Jason) Puncheon further forward. That gave us more options and we carried that on in the second half. That second-half performance was good but we didn't have it on easy street at any stage.
"It was difficult for us with a couple of injuries so I wanted certain fringe players to get a game, but the problem was with such a short turnaround I had to use four or five players who played on the weekend or will be needed next weekend."
- 55CooperSubstituted forReidat 61'minutes
- 14CarrollSubstituted forAsoroat 77'minutes
- 46Baker-RichardsonSubstituted forCullenat 78'minutes
- 34KellySubstituted forWardat 62'minutes
- 15SchluppSubstituted forTownsendat 62'minutes
- 20WilliamsSubstituted forKaikaiat 76'minutes
- John Brooks
- Shots on Target
Second Half ends, Swansea City 0, Crystal Palace 1.
Attempt missed. Liam Cullen (Swansea City) header from the centre of the box is too high. Assisted by Yan Dhanda with a cross.
Offside, Crystal Palace. Jairo Riedewald tries a through ball, but Alexander Sørloth is caught offside.
Foul by Aaron Wan-Bissaka (Crystal Palace).
Liam Cullen (Swansea City) wins a free kick on the left wing.
Foul by Andros Townsend (Crystal Palace).
Liam Cullen (Swansea City) wins a free kick in the defensive half.
Attempt missed. Sullay Kaikai (Crystal Palace) right footed shot from outside the box misses to the left. Assisted by Andros Townsend.
Attempt saved. Andros Townsend (Crystal Palace) right footed shot from outside the box is saved in the bottom right corner. Assisted by Alexander Sørloth.
Attempt saved. Jason Puncheon (Crystal Palace) right footed shot from outside the box is saved in the centre of the goal. Assisted by Aaron Wan-Bissaka.
Attempt saved. Sullay Kaikai (Crystal Palace) left footed shot from the left side of the six yard box is saved in the centre of the goal.
Attempt blocked. Andros Townsend (Crystal Palace) left footed shot from outside the box is blocked. Assisted by Ryan Inniss.
Attempt blocked. Sullay Kaikai (Crystal Palace) right footed shot from outside the box is blocked. Assisted by Alexander Sørloth.
Attempt saved. Max Meyer (Crystal Palace) right footed shot from outside the box is saved in the top right corner. Assisted by Aaron Wan-Bissaka.
Attempt blocked. Jason Puncheon (Crystal Palace) left footed shot from the centre of the box is blocked. Assisted by Max Meyer.
Substitution, Swansea City. Liam Cullen replaces Courtney Baker-Richardson.
Substitution, Swansea City. Joel Asoro replaces Tom Carroll.
Jason Puncheon (Crystal Palace) wins a free kick on the left wing.
Foul by George Byers (Swansea City).