A youthful Juventus side crushed SPAL on Wednesday to set up a Coppa Italia semi-final against Inter Milan after 10-man Atalanta booked a place in the last four by beating Lazio in a Bergamo thriller.
Morata put Juve in front from the spot and Frabotta scored in a second before half-time.
Pirlo’s side have now won seven of their last eight games and return to Serie A action on Saturday with a trip to Sampdoria, while SPAL are at home to Monza the following day in Serie B.
The visitors had a brief moment on top in the second period but further goals from Dejan Kulusevski he added the third with a composed finish after 78 minutes and Chiesa followed, sealing a straightforward path through for Pirlo’s men.
Andrea Pirlo chose to rest star man Cristiano Ronaldo for the encounter and handed a first-team debut to 19-year-old midfielder Nicolo Fagioli from the start, while youngsters Alessandro Di Pardo and Cosimo Da Graca debuted from the bench.
In Bergamo, Atalanta eliminated Lazio despite spending most of the second half with 10 men, setting up a semi-final against the winner of Thursday’s clash between Napoli and Spezia.