Cremonese will play Fiorentina in the last four of the Italian Cup after Serie A's bottom club inflicted a surprise 2-1 defeat on Roma on Wednesday.
Davide Ballardini's side are yet to win a league game in their first top-flight season since 1996 but have a two-legged semi-final to look forward to thanks to Cyril Dessers' 28th-minute penalty and a Zeki Celik own goal shortly after half-time.
Roma exit with a poor performance from an initially second-string team nothing like the display Jose Mourinho's team put in at Napoli on Sunday.
Mourinho was so enraged by his side's first-half efforts that he made four changes at the break but not even the introduction of Paulo Dybala and Tammy Abraham was enough to turn the result in Roma's favour despite Andrea Belotti's late strike for the hosts.
Among those left out was Nicolo Zaniolo, who sent an open letter to Italian news agency ANSA on Wednesday saying he was "at the complete disposal of the Roma family" following a public transfer spat which led to him fleeing Rome in apparent fear for his safety.
The Italy international has been frozen out by Roma, reportedly at the request of the club's American owners, after putting in a transfer request, refusing to be selected for matches and then turning down a 30-million-euro move to Bournemouth.
On Saturday Mourinho said that Zaniolo had told him and his teammates that he never wanted to play for Roma again.
The semi-final line-up will be completed on Thursday when Juventus host Lazio in Turin, with the winner facing Inter Milan.