A late flurry of goals in an otherwise largely uneventful encounter handed the visitors a comprehensive victory at the Academy Stadium, with Charlie Brown, Tariq Uwakwe and Juan Castillo adding to George McEachran’s first-half strike.
Lorenzo Gonzalez netted a late consolation for the Blues from the bench in a rare positive on a frustrating afternoon.
Paul Harsley’s side looked to continue the fine league form, which had lifted the young Blues to the top of the table with 13 points from seven games.
The EDS boss had admitted beforehand this game marked the start of a potentially crucial fortnight for his side and the hosts sought to gain an early advantage, as Nabil Touaizi – returning to the starting XI after suffering a broken jaw – forced Jamie Cumming into a stop at his near post on four minutes.
Taylor Richards then tried his luck from distance but found the Chelsea shot-stopper equal to his effort, while Adrian Bernabe also struck from range to no avail.
Ian Carlo Poveda and Touaizi combined well in the area, only for the former to skew over the bar, as City continued to look the most threatening.
The half seemed to be petering out after the half-hour mark with the visitors’ only real chance almost catching out – thankfully, the ball bounced over the bar.
The away side struck a hammerblow just before the break however, when the hosts failed to clear a corner. The ball fell kindly for McEachran and the Chelsea man struck a half-volley past Grimshaw to gain a half-time lead.
The opening exchanges of the second half bore little in terms of goalmouth action, but three goals in 11 minutes of the final quarter sprung the game into life – and the visitors’ favour.
Substitute Brown doubled the advantage from close range with 17 minutes of normal time to go, and Uwakwe put the game beyond doubt with a backpost header four minutes later.
Castillo added Chelsea’s fourth, sprinting clear and slotting into the corner to complete the rout.
There was time for City to grab a consolation, as Gonzalez converted Matondo’s cross – but it did little to ameliorate the result, which did perhaps flatter the London outfit.
What it means...
City drop to fifth in the table, while Chelsea move up to third - level on points with leaders Everton and second-placed Arsenal.
How we lined up..
The Blues were bolstered by the return of Touaizi, who had been sidelined with a broken jaw.
The striker led the line upfront, flanked by wingers Benjamin Garre and Poveda.
Bernabe and Richards were employed in the middle with Iker Pozo protecting the defensive backline of Alpha Diounkou, Colin Rosler, captain Cameron Humphreys and , who shielded shot-stopper Grimshaw.
The young Blues return to UEFA Youth League action with a trip to Shakhtar Donestk on Tuesday (10am BST) before travelling to Everton in the Premier League 2 on Saturday 27 October.