Yup, that's the fact Chelsea played well today by scoring 5 goals and what's interesting is that the 5 goals were scored by 5 different players meaning each player takes a role and builds chemistry, we can imagine how dangerous Chelsea will be if they continue to play like this. West Ham is not a weak team, they often trouble other strong teams and here Chelsea is playing away well, as the home team West Ham should not have conceded 5 goals and that proves Chelsea's quality.
Chelsea woke up and performed outstandingly to destroy West Ham in this match that is helpful for them to come back to a Premier League title race with other big clubs. Beating West Ham with this big winning result brings not only three points to Chelsea point collection but also rescues their chances of winning Premier League title.Potter is such a terrible manager. He failed on his two opening games, and deserve the sack. He's not good, and out of his depth at a high level of competition like EPL. He shall leave football for the good. I also expect him to be hammered by the hammer(Westham) very soon. 
Two first matches, two defeats and while a big defeat under Chelsea is understandable as Chelsea are a very strong team that can destroy any club including PSG, are truly bad results from Potter and West Ham. With these bad results, Potter will face with considerable pressure in next several matches and he must improve West Ham performances and get points, otherwise he will be sacked in coming weeks.