At the end of a fractious match it is common enough to see a manager step in to dissuade one of his players from confronting the referee. At the Mapei Stadium on Saturday the roles were reversed. Paulo Fonseca was getting ready to share some choice words with the officials at the end of Roma’s 4-2 defeat by Sassuolo, before Edin Dzeko intercepted him.

“He told me not to get angry because the referee was not the one responsible for our defeat,” explained Fonseca. “I liked that he said that, and I agree with him – even if I still don’t understand how we finished this match with seven players booked and one sent off.”

It had indeed been an imperfect performance from the referee, Luca Pairetto, who flashed his cards too easily. Yet Dzeko was also right to remind his manager of the context. Roma had fallen 3-0 behind inside 26 minutes against opponents who had never beaten them in 13 previous meetings. The red card to Lorenzo Pellegrini did not arrive until midway through the second half.

The disintegration of Fonseca’s team, just a week after they had outplayed Lazio in the Rome derby, was something to behold. At kick-off they sat 16 points, and 11 places, ahead of Sassuolo in the table. Yet right from the first whistle they were chasing shadows.

Both teams lined up in ostensibly similar 4-2-3-1 formations. Yet where Roma were rigid, Sassuolo’s shape was constantly evolving – in large part thanks to the prodigious efforts of their journeymen forwards Francesco Caputo and Filip Djuricic.

Notionally lined up in the two central attacking positions, they alternately dropped deep when their team had possession, not just into midfield but at times so far deep and wide that they looked more like supplementary wing-backs. If that sounds like an act of caution, in reality it was the opposite.

The plan worked perfectly. Time and again Roma found themselves outnumbered in the middle of the park, in turn causing the centre-backs, Gianluca Mancini and Chris Smalling, to lose their own positional discipline as they rushed to close the wide-open spaces in front of them.

Djuricic had all the time in the world to pick out the through-ball on to which Caputo strode to side-foot home the opening goal. Sassuolo’s second arrived at the end of a breakneck counter, the same striker presented with an easy finish after Domenico Berardi’s first-time pass. By now Roma were in disarray. Manuel Locatelli pounced to intercept an attempted clearance, heading it down for Berardi, who again needed only one touch to serve Djuricic for 3-0.

Roma at least made a game of it. Fonseca changed his team at the interval, sending on Bruno Peres for Davide Santon. Dzeko’s 55th-minute header – his 100th goal for the club – gave them hope, and even after Pellegrini received his second booking, they were able to close the gap further, Jordan Veretout converting a penalty after Jérémie Boga handballed.

But the latter player made amends for Sassuolo with a spectacular goal of his own, cutting in from the left and curling the ball into the far top corner. When a player as gifted as this decides to take matters into his own hands, sometimes there is not much anyone can do.

What a striker from Jeremie Boga 😍



🚀 The Ivorian netted his 6⃣th Serie A goal of the season to re-store Sassuolo's 2⃣ goal advantage 🆚 Roma



😯 Roma trailed 3-0 at HT, the first time they have done so in 8 years



📉 This was Roma's first ever Serie A loss to Sassuolo pic.twitter.com/wozkKRkHQ6 — Premier Sports 📺 (@PremierSportsTV) February 3, 2020

Boga, a graduate of Chelsea’s academy, has produced moments like this against other teams already this season – including a spectacular consolation in his team’s 4-3 defeat at home to Inter. No wonder Roma themselves made an approach to take him on loan last month. The 23-year-old Ivorian winger has admirers at other leading European clubs besides.

Roberto De Zerbi’s Sassuolo, more broadly, have played with a velocity and finesse at times this season that make it hard to understand what they are doing in the bottom half of the table. With greater consistency this team could be fighting for a Europa League place.

None of which can disguise the fact that Roma were poor. They were missing a number of important players – Nicolò Zaniolo, Amadou Diawara and Davide Zappacosta have all been lost to long-term injuries while Henrikh Mkhitaryan has had a series of smaller ones – but have now lost four times in seven games across all competitions this year.

Paulo Fonseca was angry with the referee at Roma’s defeat but acknowledged that he was not the reason his side were beaten. Photograph: Elisabetta Baracchi/EPA

Fonseca confessed at full time that he was at a loss to explain the drop-off in his team’s performance after that strong showing against Lazio. “I’m worried,” he said, and many supporters will feel the same. This loss allowed Atalanta, despite a disappointing draw of their own at home to Genoa, to pull level in fourth place.

A more active January transfer campaign would have been desirable to shore up a depleted squad but that was never likely with the ownership currently negotiating to sell the club to a consortium led by the American billionaire Dan Friedkin. Fonseca did give second-half debuts to the new arrivals Carles Pérez and Gonzalo Villar but it would be optimistic to expect a transformative impact from a pair of 21-year-olds with limited first team experience at Barcelona and Elche.

The situation is not ideal but Roma must work with what they have. As Dzeko reminded his manager on Saturday, that starts with a refusal to seek out scapegoats, after a performance as disappointing as this.

Talking points

• What a moment at San Siro on Sunday, as Daniel Maldini made his Milan debut – 36 years after his father Paolo and 66 years after his grandfather Cesare had done the same. He was on the pitch for only a few injury-time minutes – too little to offer any serious analysis – but his introduction certainly enthused supporters during an otherwise frustrating draw with Verona. Unlike Paolo and Cesare, he is not a defender but a forward – one who has played as a striker, winger and No 10 at different times for the academy side. With Krzysztof Piątek having gone to Hertha, there may be greater opportunities ahead.

Daniel Maldini making his brief debut. Photograph: Matteo Bazzi/EPA

• Christian Eriksen made his debut but it was once again Romelu Lukaku who rescued Inter – breaking the deadlock with a clever finish after 64 minutes of desperately drab football away to Udinese. A further penalty made the result comfortable and took Lukaku to 16 goals for the season …

• … which, frankly, still looks paltry next to Ciro Immobile’s 25 in 21 games. Where Roma took a step back from their derby performance, Lazio were back to their devastating best as they trampled Spal 5-1.

2⃣ more goals for Ciro Immobile on the weekend 🆚 SPAL, including this GOTW contender



🔥 He now has 2⃣5⃣ Serie A goals this season 👉 AC Milan have scored 2⃣3⃣ 😯



🎯 He's scored more goals than anyone else in Serie A over the last 10 seasons - 1⃣2⃣3⃣ pic.twitter.com/o221w2lQky — Premier Sports 📺 (@PremierSportsTV) February 3, 2020

• Some part of me does wonder whether Cristiano Ronaldo feels some irritation at Immobile’s ludicrous scoring pace. Clearly there is no comparison between the players but the Lazio striker continues to sit six goals clear at the top of the scoring charts, which is somewhat distracting people from the Portuguese player’s own relentless scoring form. His double against Fiorentina took him to 10 goals in his last six games across all competitions. He has scored in nine consecutive league games.