Frosinone ended Como’s unbeaten start to the Italian championship with a 2-0 win in the fifth round.
Giacomo Calo put the hosts ahead in the 14th minute, finishing a Frosinone attack to give them an early lead.
Frosinone continued to threaten before the interval and doubled their advantage in stoppage time. Giorgi Kvernadze scored in the third added minute after being set up by Romano Schmid.
Como increased the pressure after the break as they attempted to change the course of the match. However, Frosinone defended effectively and goalkeeper Lorenzo Palmisani made several important saves to keep out dangerous efforts from the visitors.
Frosinone held on to their advantage until the final whistle to secure three points. The result was Como’s first defeat of the season.