The Blues completely dominated the opening proceedings and went into a deserved lead when Enzo Fernandez floated the ball into the box for Joao Felix to meet the ball with a cute volley and open his Chelsea account.
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However, West Ham played themselves back into the game and equalised against the run of play as Emerson netted his first Premier League goal to equalise against his old club.
Both teams then battled to find a winner in the second half, and bar a Tomas Soucek effort that was ruled out by VAR for offside, neither side could find a way through and the capital clash ended all square.
In Felix, Chelsea have a match-winner and someone who looks like he could really ignite the attack for the remainder of the season. Fernandez also showed what he offers and will only get better as he familiarises himself with the team and the league.
Despite their early dominance of the game, Chelsea failed to finish off the opposition. In the opening half-hour it looked like there was only one team in it and the Blues will be disappointed how they let West Ham back into the game.
Manager rating (out of 10)
Graham Potter, 6 - Potter threw all four of his new signings into the starting XI and for half an hour it looked as though it would pay off. He will be disappointed his team didn't turn their early dominance into a more commanding lead that the Hammers wouldn't have been able to come back from.
Player ratings (1-10 with 10 = best)
GK Kepa Arrizabalaga 6 - A virtual spectator for most of the game, especially in the first half where he was only called into action from a routine save from Michail Antonio -- apart from when he had no chance with the Hammers' goal.
DF Reece James 5 - Not the most effective performance from the England defender who struggled to impact the game from an attacking point of view. Was caught ball-watching for West Ham's equaliser but kept the home side's attack at bay in the second period.
DF Thiago Silva 6 - The defender, who has just signed a new contract, was Chelsea's best defender and didn't give Antonio very much the whole game. Also pulled off a last-ditch tackle in the first half to prevent the West Ham striker from converting.
DF Benoit Badiashile 6 - Conceded his first Chelsea goal since his January move from AS Monaco and had a good tussle with Antonio, resulting in a second-half booking. Had a couple of half-chances to open his Chelsea account from first-half corners.
DF Marc Cucurella 6 - Saw a lot of the ball on the left flank, but struggled to convert his possession into any real danger going forward. There were though some early signs of a partnership developing between him and Mudryk before both left the field.
MF Ruben Loftus-Cheek 5 - Played a key part in Chelsea's good start, where he helped dictate play in the centre and carried the ball forward with some driving runs into the box. Faded as the game went on.
MF Enzo Fernandez 7 - The Premier League's record signing looked every bit the star with a first half where he controlled the game. Constantly found room in the midfield and set up the goal for Felix, but the Argentine failed to keep up the same level of performance for the whole game.
MF Noni Madueke 6 - Lots of running and willingness on his first start for the club, but nothing really seemed to come off. He constantly looked to cut in on Chelsea's right flank, but it never materialized into anything.
FW Joao Felix 8 - The best player on the pitch in the first half as West Ham failed to deal with his movement and threat from behind. Ghosted past the defence to open his account for the club with a neat finish, it always looked like any danger would come from the feet of the Portuguese star.
FW Mykhailo Mudryk 5 - Saw a lot of the ball in the first half but never really got into the game and was well-marshalled by the West Ham defence. His quick feet were a clear danger, but it never produced an end result.
FW Kai Havertz 6 - Bright and effective in Chelsea's early dominance and was unlucky to see a goal ruled out for offside in the first half. Impact diminished in the second period, but remained an outlet as the highest point of Chelsea's attack.
Substitutes (players introduced after 70 minutes get no rating)
DF Ben Chilwell NR - Pleasing to see the England defender back and linked up well with Havertz to fashion a chance.
FW Hakim Ziyech NR - Offered very little in his cameo and gave away a silly foul that almost cost Chelsea the game before Soucek's goal was chalked off for offside.
MF Conor Gallagher NR - Late sub to give the midfield engine more legs as Loftus-Cheek and Fernandez faded.