The French forward struck in the second half to settle a tight contest and spark celebrations among Palace supporters.
Speaking after the final whistle, Mateta struggled to contain his emotions as he reflected on the magnitude of the achievement.
He described it as a “fantastic” feeling to help a club that, not long ago, would have viewed European silverware as a distant dream.
"I feel fantastic! I feel fantastic! We did it! First time in Europe and we did it. Now I just want to celebrate. This guy (Joel Ward) has to celebrate with us," Mateta told TNT Sports.
"We gave everything. I told you about the intensity they will have and I am tired right now, I gave everything. That's why we won today. I am always with the fans. They have supported me a lot as a player. They are always behind us. We did it for them too."