Despite creating a host of chances, the Blues slipped to defeat in Aldershot after goals in either half from Luke McCormick and Daishawn Redan.
And to add to the frustration, both Cameron Humphreys and Taylor Richards were sent off after each picked up two yellow cards after the break before Jeremie Frimpong also saw red after the full-time whistle.
On a wet and testing evening at the EBB Stadium in Hampshire, the Blues were looking to kick on from last Sunday’s 1-0 win over Aldershot.
And City enjoyed plenty of possession and created numerous first-half chances which kept home keeper Karlo Ziger more than busy.
Early on, he produced a fine stop to deny Ian Carlo Poveda while Felix Nmecha’s smartly taken shot on the half hour rippled the side netting.
However, it was Chelsea who made the breakthrough on 25 minutes, with Luke McCormick finding the target with a first-time curled effort from the edge of the area.
The Blues sought an instant response with Ziger keeping out a sweetly-struck Nmecha free-kick before he foiled the Blues again after Richards had released Poveda.
Adrian Benabe then saw his shot parried away by the Chelsea stopper.
And right on half-time Nabil Touaizi’s shot from the edge of the area clipped the top of the Chelsea bar.
Straight after the break, Poveda ran at the Chelsea defence but couldn’t keep his shot down.
However, on 58 minutes City’s task became much harder after Cameron Humphreys was sent off after picking up his second yellow card of the night.
With 20 minutes left, Ziger then had to come off his line to beat Gonzalez to the ball as he latched on to Bernabe’s through-ball.
At the other end, Grimshaw kept out Uwakwe’s free-kick before Poveda threatened once more with the clock running down.
But two minutes into stoppage time, Chelsea sealed the win. Lamptey opened up space on the right flank and found Redan, who finished from a couple of yards out.
And the Blues’ frustration then got the better of Taylor Richards who was also shown a second yellow card.
Then just to cap off a night to forget, Jeremie Frimpong was also red carded after the full-time whistle.
What it means
The result saw City remain in eighth place in the Premier League 2 table.
How we lined up
Dan Grimshaw was in goal with Tyreke Wilson, Cameron Humphreys, Eric Garcia and Colin Rosler in defence.Taylor Richards, Ike Pozo and Adrian Bernabe were deployed in midfield with Felix, Ian Poveda and Nabil Touaizi up-front.