Premier League: Chelsea end Liverpool's perfect start, United suffer Hammer blow
The result left Liverpool in second place, with champions Manchester City, who beat Brighton earlier on Saturday, top on goal difference.
London: Chelsea ended Liverpool's perfect start to the Premier League season as the title contenders drew 1-1 at Stamford Bridge on Saturday.
Liverpool had won all six of their previous league matches this term but, having lost to Chelsea in the League Cup in midweek, they fell behind on Saturday when Eden Hazard gave the hosts a 25th-minute lead at Stamford Bridge.
But Daniel Sturridge's brilliant long-range strike a minute from full-time preserved Liverpool's unbeaten league run.
This result left Liverpool in second place, with champions Manchester City, who beat Brighton 2-0 earlier on Saturday, top on goal difference.
City showed the gulf in class between the two sides of Manchester as Brighton, who beat United earlier this season, were comfortably seen off at the Etihad thanks to goals either side of half-time from Raheem Sterling and Sergio Aguero.
United's worst league start in 29 years means they are also five points adrift of Tottenham and Arsenal in the race for a place in the top four, with the North London clubs 2-0 victors over Huddersfield and Watford respectively.
Miserable week
Defeat at the London Stadium compounded a miserable week for United manager Jose Mourinho, whose side were also dumped out of the League Cup by Derby on penalties and held at home by Wolves last weekend.
Mourinho's switch to a three-man defence backfired as Felipe Anderson and Victor Lindelof's own goal gave West Ham 2-0 half-time lead.
"After the result on Tuesday the team obviously needs positive things, positive feelings and to start losing after five minutes is not that positive start that you need," said Mourinho.
Paul Pogba was also under the spotlight after being stripped of the vice-captaincy by Mourinho in midweek and a frosty training ground exchange between the pair on Wednesday.
However, the French World Cup winner failed to make an impact before he was substituted 20 minutes from time.
Marcus Rashford came off the bench to briefly give United hope by pulling a goal back, but just three minutes later Marko Arnautovic exposed more poor United defending to seal West Ham's first home league win of the season.
City slickers
City face a big trip to Hoffenheim in the Champions League in midweek having lost at home to Lyon to open their campaign, but they have suffered no such domestic struggles in defence of their title.
Leroy Sane's pace again made a big impact as the German's low cross was tapped home by Sterling at the back post for his fourth goal of the season.
City could have had many more goals, but had to wait until 25 minutes from time when Aguero slotted home after a neat one-two with Sterling.
"Every time we lost the ball, we recovered and attacked with players at the edge of their penalty box. That is a dream for us," said a delighted Pep Guardiola.
Tottenham moved into fourth as Harry Kane scored twice in nine first-half minutes to easily see off struggling Huddersfield.
"It was a grind out there, the kind of games where it feels good when you win, a battle with tough defenders," said Kane.
Arsenal stayed level with their north London neighbours on 12 points with a seventh straight win in all competitions as a Craig Cathcart own goal and Mesut Ozil's finish earned all three points in the final 10 minutes at the Emirates.
Everton ended a four-game winless run to beat Fulham 3-0 as Gylfi Sigurdsson made amends for missing an earlier penalty to score twice either side of Cenk Tosun's first goal of the season.
Wolves' impressive return to the top flight continued thanks to late goals from Ivan Cavaleiro and Jonny Castro to earn a 2-0 win over Southampton.
Newcastle remain winless and in the bottom three after a 2-0 defeat at home to Leicester with two of England's World Cup squad Jamie Vardy and Harry Maguire on target.