Chelsea punished a dire defensive display from West Ham as Nicolas Jackson’s first-half double helped Enzo Maresca’s side secure an easy 3-0 win at the London Stadium.
Jackson opened the scoring early on when West Ham defending, described as "criminal" by Michael Dawson on Soccer Saturday, allowed him to beat Alphonse Areola on the angle having exchanged passes with Jadon Sancho and carried the ball forward unopposed.
Julen Lopetegui's side completely switched off again soon afterwards, leaving Moises Caicedo free to send Jackson cantering through on goal for a coolly-taken second.
West Ham tried to muster a response and were contentiously denied a penalty when VAR ruled Wesley Fofana's pull on Crysencio Summerville not to be "sustained holding".
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But any hopes of a recovery were dashed straight after half-time when Chelsea carved through West Ham yet again, with Jackson this time turning provider to set up Cole Palmer for an emphatic finish following a rapid counter-attack.
Following their reverses against Aston Villa and Manchester City, West Ham have now lost their first three home games of a league season for the first time in their history. The home fans aired their dissatisfaction with new boss Lopetegui by booing his decision to substitute Summerville, and booing again at the final whistle.
While the Hammers continue to struggle at home, Chelsea make it three wins out of three on the road in the Premier League, continuing an encouraging start for Maresca which contrasts sharply with that of his opposite number at West Ham.
The victory could easily have been even more emphatic, with Noni Madueke and substitutes Joao Felix and Christopher Nkunku all spurning second-half chances in front of watching co-owners Todd Boehly and Behdad Eghbali, who put on a united front amid recent reports of a rift and visited the away dressing room afterwards.
"It's always good for them when we win games, especially as they were both here," said Maresca. "We could give them a good moment. They were in the changing room and happy.
"The results and the points are always important but for me the main target is to see how we progress as a team and I think we are improving many things."
Lopetegui: Fans have a right to boo
West Ham boss Julen Lopetegui: "Very, very frustrated today, for sure. We had big expectation for the match.
"We worked a lot to prepare for it. I have to review it again but it has been a very soft way to lose. We suffered two early goals where we have to do better.
"We had chances and more of the ball, but goals are more important. We were not consistent. In the Premier League, if you want to compete, you have to be consistent."
On the boos of the home fans: "It's normal when you lose. They have the right to complain. We know this. That's why we are the only solution to change this.
"We have to do better, all of us, but first of all, me. We have to improve but it's the start of the season. We have a lot of time to do this."
Maresca: We are on the right path
Chelsea boss Enzo Maresca: "Very pleased with the performance and three points. That is most important, the clean sheet also. It has been a complete performance, so we are very happy.
"The way the players are buying [into] the idea and the different style since I arrived has been top. And also the way we are working off the ball.
"Today, the performances from Nico and Cole were top not only because they scored. The way they worked was top. If we understand we need that, probably we can build something important.
"I think we are on the right path, in the right direction, but this is a long journey. We are in a good moment. It looks like everything is fine when you win. But not everything is fine.
"We could do some things better. But it is just a matter of time. The most important thing is how the players buy [into] what we do and they have done that."
Palmer: We all know Jackson's a top player
Chelsea forward Nicolas Jackson to TNT Sports: "(I am) growing higher with my team-mates, they help me a lot and they have confidence in me.
"We keep going. This one is finished and next week we go onto another one. The most important thing is for the team to win.
"I am happy to play always. To fight for the team and the team to win is the most important thing."
Chelsea's Cole Palmer to TNT Sports: "A tough place to come and a good three points, we are happy.
"Everybody knows he [Jackson] is a top player - he needs to keep going. The Chelsea fans and players rate him highly - we know what he is capable of.
"There will always be noise, we try to block it out and listen to the manager. We have a good manager and it can only help us to get better."
Analysis: Jackson vindicates Maresca's big call
Sky Sports' Nick Wright:
Christopher Nkunku's winner from the bench against Bournemouth led to a clamour for the France international to start at the London Stadium but Maresca gave his backing to Jackson as his first-choice striker before the game and he repaid his faith in style.
Jackson was helped, of course, by the dreadful West Ham defending that allowed him to waltz through for each of his two goals. But he was still required to finish coolly and he did just that.
His double takes him to four Premier League goals for the season and 18 since the start of last term. He also has seven assists. They are strong numbers for a 23-year-old striker who was had to withstand criticism. He is making the No 9 spot his own.