Napoli president Aurelio de Laurentiis is delighted for Edu Vargas after his hat-trick in midweek.
The much-maligned Chilean striker struck in the Europa League.
De Laurentiis said: "It's a pity for those who turned their noses up at Vargas, because they're going to have to change their minds. We don't buy players for no reason, as there is a selection process performed with an almost maniacal sense of precision.
"The time when bigger clubs would snatch champions from our grasp is gone.
"We are an extraordinary group, a virtuoso network enjoying their football and who always want to win. Mazzarri is the first to feel that way."