Tielemans struck the only goal of the game on 12 minutes to move Villa level on points with fifth place Chelsea.
He said afterwards: "All our games, we know we have to win them to have a chance to be in the Champions League next season.
"It is the biggest European competition club wise. We have had a taste this season and we want to do it again.
"This afternoon was a good win. A tough opponent, Fulham are a very good team. We could have finished the game earlier, but credit to the guys. Good fight and good win."
On his goalscoring header, Tielemans said: "It is just getting in the good place at a good moment - we practiced this corner kick in training and it went well.
"To have a better good difference for us is key towards the end now. We need to improve on that definitely."