The first half of the game ended goalless with both sides lacking the killer instinct to finish off some very promising moves.
The second half also seemed to be going the same way till Jordan Opoku struck for the second successive home game to give the Blues a 1-0 win.
The game started well for the west Africans as they looked to stamp their authority by attacking early on in the game, but they were nearly caught out at the other end against the run of play.
Motebe Kidiaba then had to be alert to gather the ball after spilling the initial shot of Abdul Basit from just inside the box.
The Berekum boys though still kept working at the Mazambe defence to no avail.
The game then evened out with the Ravens starting to grow into the game with Collins Addo having to tip over a dangerous cross with a number of forwards lurking.
Chelsea had to make forced substitutions with Yaw Alexander coming on for Ahmed Adams who sustained an injury.
Mphela Mwaki also suffered a nasty head injury after a clash with Abdul Basit and had to be stretched off.
Both sides saw out the rest of the game with no real penetration in attack with the Chelsea back acting swiftly to snuff out a couple of good looking moves to send the teams in level.
The second half started as the first for the debutants, but once again they failed to finish off the move as Joseph Ato Bissah was beaten to a perfectly weighted through ball.
The Congolese nearly made them rue the missed chance seconds later but a series of well-timed last ditch tackles in the 18-yard box got them out of a tight situation.
Richard Kissi Boateng then showed some initiative with a couple of well-timed runs down the left hand side of the Chelsea attack, but the overriding theme of the game continued as nothing came out of both moves.
Tresor Mputu Mabi and Mbwana Samata then managed to force Addo into a couple of brilliant saves with powerful drives from just outside the box in a three-minute spell where the Chelsea defence looked stunned.
Mazembe then had to rely on a last ditch tackle themselves to prevent substitute Ibrahim Issaka from converting a very dangerous cross across the face of goal.
Rainford Kalaba then benefited from a deflected Mputu shot, but his curled strike from just inside the box was marginally off target.
Ngandu Kasongo then wasted a glorious chance, skying his effort after being set up in the box with no marker.
The stalemate was finally broken by Opoku, who controlled Solomon Asante’s lobbed ball brilliantly with his chest before dinking the ball over the onrushing Kidiaba to open the scoring in the 80th minute.
The Blues then managed to see out the rest of the game to finish the campaign on a high.
Chelsea won two, drew three and lost one of the six group games losing out on a semi-final spot to Mazembe who finished a point above them on 10 points.