Crystal Palace are close to the final, as they achieved a big "break" in Krakow tonight - 3:1
Ismaila Sarr gave the Premier League team the lead after Jean-Philippe Mateta assisted in the 21st second of the game, scoring the fastest goal in the history of the youngest UEFA club competition.
The home team equalized early in the second half with a goal from Oleg Očeretko.
Daichi Kamada restored the away team's lead after scoring in the 58th minute.
The final score was set by substitute Jorgen Strand Larsen in the 84th minute.
Rayo celebrated with a minimum score, and the only goal of the match was scored by Alemao in the 54th minute.
The second leg is scheduled for next Thursday.