His ability was first recognized by Guido Reni and Ciriaco Mattei, which led Domenico Passignano and Cavalier D'Arpino to employ him.

The Marchese Vincenzo Giustiniani commissioned paintings from him, including Christ Healing the Blind and Christ Raising the Son of the Widow of Nain (both of which were ultimately purchased by John Ringling and bequeathed to the John and Mable Ringling Museum of Art upon his death).

[1] During his stay in Rome, he also completed The Flight into Egypt (now in the Museum & Gallery collection), which may also be the work described by biographer Raffaello Soprani in 1674.

He writes: “One of the most famous performances by Fiasella in Rome was the picture representing the Holy Virgin with Saint Joseph and the Infant Jesus on their way to Egypt.

[3][4] He collaborated occasionally with the Flemish born painter Giacomo Legi who lived and worked in Genoa.