While Lille got a goal to take back to France for the return leg, Fonseca bemoaned his opponents' style.
I don't understand what's happening at the moment, I don't understand how it's possible to foul in the area," said Fonseca of Villa's first goal through Ollie Watkins.
I understand it's difficult for the ref but with VAR it's incredible they miss these things.
It's not good what's going on for football here, they must look at what's going on at the moment.
It's not football, it's blocking like in basketball. The first goal was a clear foul and a clear block."
I'm satisfied with the courage of my players but at the end of the day, we've lost," added Fonseca.
After that I know that it's a difficult match, they've got great players, a great coach and a lot of experience so they have certain advantages.
But I must continue to believe it's possible (to win)."