Goalscorer Alvaro Morata felt Chelsea made a significant statement by coming from behind to beat Atletico Madrid 2-1 at Estadio Wanda Metropolitano.
Antoine Griezmann's penalty just before the break put Atletico in control but Morata headed in his seventh goal in eight games for Chelsea before Michy Batshuayi struck with the final kick of the game.
The dramatic finish gave the Blues two wins from two Champions League Group C games ahead of a double-header against Roma.
'Today was a very important test against a side that have reached the Champions League final in the last few years,' Morata told BT Sport.