Fiorettina beat Roma 2-0 on Tuesday in the latest Serie A clash of the two Italian sides, a result that means they remain in third place and two points clear of the relegation zone.
It was Fioretti’s fifth win in a row in Serie A, and the first time they have lost in front of a crowd of more than 35,000 in the competition.
Filippo Inzaghi’s side will now have to fight on for their survival in Serie B, which they are currently holding on to.
It was the first victory for Roma since March 2014, and their fifth in a possible seven matches.
“This victory was the result of a difficult season, but we are looking forward to the rest of the campaign,” said coach Matteo Darmian.
“The team has grown in the last year.
This is our best performance yet.”
The win also gave the Giallorossi the second-best defensive record in Serie D, having conceded nine goals in nine matches.
Roma have conceded five goals in five Serie A matches this season, and will now be without Andrea Ranocchia, who has been ruled out of the next two games due to a knee injury.
The Giallorian side are also without goalkeeper Matteo Pianaro due to injury, as well as centre-back Lorenzo Insigne, who is out for a month after having a cruciate knee ligament injury in April.
Despite their early season struggles, the Gialls have been solid in their first six league games.
A 1-0 victory over Sassuolo in March put them back in the title race, and they then lost 3-0 at Sampdoria on the final day of the season to fall out of contention.
Fiorentini will now hope to get back to winning ways, with a game against Sampdori at the San Siro on Saturday.
Roma and Sampdora are the two teams that are currently in fourth and fifth place respectively, but there is still a lot of football left to play.
Pietro Mauri’s side are in second, three points behind second-placed Juventus.
They also face a trip to Fioretto in the Champions League on Monday, with their last game in Serie C taking place on Wednesday.
Both Roma and SampDoria have had the support of the national team, with Italy coach Maurizio Sarri’s side enjoying a run of five consecutive wins, with the last one coming in the 2014 World Cup.
Meanwhile, Sampdorian defender Dario Casilucci was ruled out with a knee problem on Wednesday, meaning he will miss the next four Serie A games.