Ismaila Sarr shone in a 3-1 win at home to AZ Alkmaar in the Conference League.
Palace went with a full-strength side three days out from the showdown with the Seagulls.
They finished the evening on a high at vibrant Selhurst Park after scoring an important and impressive win.
Sarr looked in great form, turning the ball home right on half-time and then, after Alkmaar pulled a goal back in the second half, racing on to Jean Philippe Mateta’s through ball to finish.
He was denied the chance to make it a hat-trick when he was substituted with Sunday’s game in mind.
Palace boss Oliver Glasner said: “He mentioned yesterday (Wednesday), a very small tightness in his hamstring.
“I said we have a game on Sunday as well, then he plays for Senegal, fortunately here in London. We have to manage the minutes.”
Sarr scored twice for Palace when they won 3-1 at the Amex last season.
The win got Palace’s European campaign moving again after they were defeated by AEK Larnaca two weeks ago.
They made just one change to the side who beat Brentford in their previous league game, with Will Hughes replacing Daichi Kamada in the heart of midfield.
Sarr and Hughes made way on 65 minutes for Kamada and Adam Wharton, who was returning after illness.
Glasner had said beforehand that Wharton was not yet 100% and he would manage his minutes, again with thoughts on Sunday.