The Primera Division side have one leg in the quarter-finals of the competition after a comfortable away win
Goals from Antonio Barragan, Federico Cartabia and Philippe Senderos saw Pizzi's men cruise to a crucial win in the first leg of their round of 16 tie, with Ludogorets missing a penalty halfway through the first half as Seydou Keita was sent off for a foul on Roman Bezjak.
"I keep saying the same thing: nobody will be able to deprive us of the illusion that we can win the Europa League," Pizzi said at a press conference.
"I am delighted that we did well here and that we can dream of bigger things. This is the result of all our hard work.
"I think we are on the right track, but the tie is not over just yet. All games are difficult. Every opponent and each situation has its difficulties.
"It was a fortunate moment that Diego saved the penalty. It would have been difficult if they levelled the scoring as we were a man down."
The two teams meet again at the Mestalla next Thursday.