Perez struck for the 2-1 win as he was barracked by home fans throughout the game.
The striker said afterwards: "It was something I expected, because since I left, that's what I've received . There were a lot of lies told after my departure, so I imagined this situation would happen, but above all, there's the crest, Real Betis, and its fans.
"I have very good memories, I was happy here, and I had a very good opportunity. That's what I'll take away."
Perez added, "My intention was to stay here, but football and life separated our paths, and that's it. I'm happy to see the manager and my former teammates again. We're going our separate ways, but we're doing quite well, and that's what matters. I was very happy here, I insist.
"There have been disrespectful acts that shouldn't be normalized in the world of football , but as I say, I'm left with the affection and good memories."