Oliver Glasner's side started brightly and nearly took the lead twice in the opening minutes as Jean-Philippe Mateta and Evann Guessand both fired wide from a pair of Daniel Munoz crosses. 

Mateta put Palace ahead in the 24th minute as he coolly sent his penalty straight down the middle after Guessand was felled inside the box by Dodo. 

Tyrick Mitchell then doubled the host's lead just seven minutes later as his left-footed strike flew across the face of goal and into the bottom right corner to put Palace in a commanding position. 

Daichi Kamada went close to adding a third, while Dean Henderson was called into action at the other end to deny Albert Gudmundsson's arrowed header. 

Both Mateta and Ismalia Sarr sent headers off target as Fiorentina offered little resistance, before the latter sealed an emphatic victory and extended Palace's first-leg lead on the stroke of full-time, powering home Kamada's cross into the top right corner.