By KIERAN GILL, MAIL SPORT REPORTER
Published: 17:59 EST, 9 December 2025 | Updated: 17:59 EST, 9 December 2025
Charles De Ketelaere could hardly believe his luck as neither Benoit Badiashile nor Marc Cucurella came to challenge him. Chelsea's defenders backed off, deeper and deeper until in their own box, and Atalanta's impressive attacker scored. Just like that, Enzo Maresca's bad week got worse.
The 3-1 loss at Leeds was embarrassing, the 0-0 draw at Bournemouth was boring, and those two performances told us why they are not yet true Premier League contenders. In all likelihood, as good as Chelsea have been as a tournament team under Maresca, this season's Champions League is bound to be beyond them also.
They won the Conference League and Club World Cup but this competition is a level above those and then some. Maresca tinkered as he likes to do. By the end, he had two right backs on the pitch in Reece James and Malo Gusto – except neither was playing in his actual position.
Josh Acheampong was. The 19-year-old academy graduate impressed overall at right back. This loss was hardly on him. But sometimes, it can feel as if Maresca is trying to be too clever for his own good, unveiling new tactical ideas and managing minutes when Chelsea needed this win.
Victory here would have helped them in their pursuit of avoiding adding that pesky two-legged play-off to their schedule. Now, the youngest side in Europe are likely to need to beat Pafos at home and Napoli away to stand any chance of a top-eight finish.
Winless in December, and with Maresca's total number of changes made to his line-ups this season now standing at a whopping 119, they are stuck in a slump. Certainly, the optimism that followed Chelsea's beating of Barcelona a few weeks back is now dropping as deep as Badiashile and Cucurella did when they ought to have been stopping De Ketelaere from scoring his winner here.
Chelsea let a lead slip in Atalanta as they suffered defeat in the Champions League on Tuesday
Reece James was unable to drag his team to a result as he played in midfield once again
Joao Pedro has come under fire for his performances as a striker, but was on the scoresheet
Jury still out on forward options
A fair few fans do not like Joao Pedro leading the line for Chelsea and it is easy to see why they are so sceptical of him as a striker. His skillset is so different to the injured Liam Delap's that he struggles to hold up the ball and, inevitably, seeing him surrender possession can be aggravating.
Nevertheless, he showed a scorer's instincts by charging into that space in the six-yard box to meet James' cross. After showing he can play at right back, centre back and in midfield, James looked like a nifty left winger with that assist for Joao Pedro. We will caveat that by saying it was a 33-year-old Davide Zappacosta, the wing back formerly of Chelsea, who he sped beyond.
James should have scored a second goal for the visitors in the 51st minute so perhaps we will not add striker to his list of positions just yet. That was costly, with Chelsea conceding their equaliser in the 55th. That came from Gianluca Scamacca, the former West Ham flop who was unmarked as he headed in De Ketelaere's cross.
Maresca said on Scamacca and De Ketelaere scoring: 'Both goals, we could have avoided them. They were easy goals.'
Italians' brave tactics pay off
Atalanta were no chumps. They may be 12th in Serie A but they won the Europa League two years ago and in this season's Champions League, they had beaten Club Brugge, Marseille and Eintracht Frankfurt since opening with a loss to Paris Saint-Germain.
The Italian side played with a brave plan which involved going man to man all over the pitch and it meant Chelsea's passing was under persistent pressure.
The Blues could do with improving their starts in games because, after alarming sluggishness at Leeds and Bournemouth, Atalanta could easily have taken an early lead here.
First, Ademola Lookman would have scored were it not for Robert Sanchez denying him. Then, it was Acheampong's turn to stop the experienced winger formerly of Everton, Fulham and Leicester with a brilliant block.
Atalanta opted to employ a man-to-man approach which meant Chelsea's passing was always under pressure
Josh Acheampong's performance gave reason for optimism as the teenager started for the first time in the Champions League
A reason to be cheerful
With half-time approaching, Acheampong was first congratulated by Trevoh Chalobah, then Moises Caicedo, and then Enzo Fernandez. It was for his last-ditch tackle to deny Lookman who had appeared through on goal. The assistant's flag was raised afterwards, but Acheampong wasn't to know at the time. His challenge was clean and, in his mind, crucial.
Starting for the first time in the Champions League, that tackle was only one of a few influential moments involving the 19-year-old. Maresca admitted after losing to Leeds last week that he regretted not using Acheampong. Indeed, the teenager is not used nearly enough for a few fans' liking. They love that he is one of their own from Cobham.
All Acheampong can do is try to take his chances to impress and, particularly in the first half, that was the case here. Just ask Lookman who he continually thwarted.
This is how it's done!
There was a nice moment before kick-off when Chelsea's Under 19s, who beat Atalanta 3-1 earlier in the day in the UEFA Youth League, emerged to find their seats at the Stadio di Bergamo directly next to the away end.
The visiting supporters sang songs for them, including 'he's got school in the morning' at 17-year-old Reggie Walsh. It was only unfortunate the men could not win like the boys.
MATCH FACTS AND PLAYER RATINGS
Atalanta (3-4-2-1): Carnesecchi 6; Kossounou 6, Djimsiti 6, Kolasinac 6 (Ahanor 71, 6); Bellanova 6 (Zappacosta 17, 6), De Roon 6, Ederson 6.5 (Musah 87), Bernasconi 6.5; De Ketelaere 6.5, Lookman 6.5 (Pasalic 87); Scamacca 7 (Krstovic 72, 6)
Subs (not used): Sportiello, Hien, Samardzic, Scalvini, Brescianini, Zalewski, Maldini
Scorers: Scamacca (55), De Ketelaere (83)
Manager: Raffaele Palladino 6.5
Chelsea (4-2-3-1): Sanchez 6; Acheampong 6.5, Chalobah 6 (Fofana 45, 6) (Adarabioyo 76), Badiashile 6, Cucurella 6; James 6.5, Caicedo 6; Neto 6 (Garnacho 66, 6), Fernandez 6 (Gusto 67, 6), Gittens 6; Joao Pedro 6.5
Subs (not used): Jorgensen, Merrick, Hato, Andrey Santos, Estevao Willian, Buonanotte, George, Guiu
Scorers: Joao Pedro (25)
Booked: Chalobah
Manager: Enzo Maresca 6
Referee: Alejandro Hernandez 6