Sassuolo put in a masterclass first half performance to lead 3-0 within 30 minutes, eventually beating Roma 4-2 in a chaotic thriller that also saw Lorenzo Pellegrini sent off.
Both teams made big changes during the January transfer window, as the hosts sold Alfred Duncan and brought back Giangiacomo Magnani, while Alessandro Florenzi was loaned to Valencia, bringing in Gonzalo Villar, Carles Perez and Roger Ibanez. Federico Peluso was suspended for this game, while Amadou Diawara, Nicolò Zaniolo, Henrikh Mkhitaryan and Davide Zappacosta were injured.
Sassuolo had just two wins in their last 10 Serie A games and had never beaten Roma in the top flight, managing only five draws from 13 meetings.
The visitors had a couple of shots on goal with Lorenzo Pellegrini and Bryan Cristante, but Ciccio Caputo showed ice-cold finishing to give Sassuolo the lead after seven minutes.
He sprung the offside trap on a Filip Djuricic through ball, changed direction to send Gianluca Mancini to ground and swept it past Pau Lopez into the far bottom corner with his right boot.
Suddenly, Sassuolo took control with a series of panicked clearances from corners, constantly haranguing Roma into giving up possession.
That led to the second goal, as the Neroverdi broke away from midfield with a wonderful quick-passing move down the right, Jeremy Toljan eventually rolling across for Caputo to turn in from seven yards for his brace.
It was still all Sassuolo, as Jeremie Boga nutmegged Jordan Veretout to go clear, testing Pau Lopez, and moments later there was a third goal.
Domenico Berardi’s through ball allowed Filip Djuricic to spring the offside trap, as Mancini was several metres behind Chris Smalling, sliding the finish beneath on-rushing Pau Lopez.
It was an extraordinary start, especially considering Sassuolo had never beaten Roma in 13 Serie A meetings and scored only once against them at the Mapei Stadium in six home games. The Giallorossi had not conceded three goals in the first half-hour of a Serie A match since September 2012 against Juventus.
Pellegrini was booked and will be suspended against Bologna. Bruno Peres replaced Davide Santon and Roma came out fighting for the second half.
Chris Smalling knocked down a set play for Dzeko’s shot, palmed on to the upright from six yards, but the move continued and the Bosnian turned in the towering header for his 100th goal in a Roma jersey.
It was so nearly 3-2 moments later, but Consigli flew to palm a Cristante volley out from under the bar, then Manuel Locatelli somehow cleared Dzeko’s tap-in off the line from point-blank range.
Carles Perez made his debut just hours after the transfer from Barcelona, but it was Caputo who should’ve had a hat-trick when scuffing the finish on a Toljan assist and allowing last man Bruno Peres to block.
Lorenzo Pellegrini’s return to his old club was not a positive one, as he received a second yellow card for bundling into the back of Berardi.
Despite that situation, Roma still got one back, because Boga charged down a Bruno Peres cross with his raised arm and Jordan Veretout converted the penalty.
It was 3-2, but moments later Boga made up for the error with a scorching strike. He burst down the left, cut inside past Mancini and hit a right-foot rocket into the far top corner. Roma had beaten Sassuolo 4-2 at the Olimpico earlier this season in the reverse fixture.
Gregoire Defrel came off the bench and forced a save out of Pau Lopez with his first touch, while Dzeko curled off target.