In a poor display, Jose Mourinho's side lacked tempo and looked sluggish as Bremen took advantage of some poor refereeing and slack defending to secure a confidence-boosting win.
They opened the scoring after 20 minutes when Eljero Elia converted a spot-kick moments after John Terry was adjudged to have handled inside the box.
Ludovic Obraniak doubled the home team's lead shortly before the interval with an excellent header before Felix Kroos—younger brother to Real Madrid's Toni—scored an 87th-minute penalty.
On the whole it was forgettable day for Chelsea, with Jose Mourinho saying at the final whistle that he "learned nothing from this game," per Goal.com's Jack Davies.
If the Chelsea boss really is of that frame of mind, we've taken the liberty of listing six things that should have caught his eye.