Alex Iwobi nabbed Arsenal's equaliser with a clinical effort in the 44th minute.
Eight minutes into the half, Chelsea were ahead as Marcus Alonso broke the down the left flank before teeing up Pedro, who slotted into the bottom corner.
There are more positive angles to West Ham though as last weekend was never really going to be a game where Pellegrini could show what his side are truly going to be about this season as Jurgen Klopp's Liverpool stripped the Hammers of any signs of displaying their attacking edge.
Chelsea beat Arsenal 3-2 in London derby thriller
Arsenal's poor start to the season continued with the Gunner's slipping to a 3-2 defeat to Chelsea at Stamford Bridge . On that occasion, they also began the campaign on home soil - going down 4-2 to Norwich at Highbury.
A team that had the joint-worst defensive record in the Premier League last season, alongside relegated Stoke City, should certainly have placed more focus on restructuring that defensive line and it could come back to haunt Pellegrini in the coming months.
Hugo Lloris was not reduced to a mere spectator, denying Tom Cairney and Ryan Sessegnon but two minutes before the break, Chambers' weak clearance fell to Lucas, who curled a first-time strike in off the left-hand post from 18 yards.
- Bournemouth have won successive Premier League games in London for the first time since their first two visits to the capital in August-December 2015.
1,400 Google Employees Protest Company’s Censored Search Engine For China
Immigration and Customs Enforcement and to end the sale of facial-recognition technology to law enforcement agencies. Google services, including its search engine, Gmail and Google Drive, are all blocked in China.
"Overall we were much better and deserved the three points, but we still need to improve".
Arnautovic nearly had a second before half-time, Begovic getting down well to keep out his deflected effort.
The visitors find themselves in a similar situation regarding new signing Jefferson Lerma, and Howe has also commented on his new signing, "We've got to remember is that he's had minimal training after the World Cup, but his performance and endurance levels are getting better with each training session". The first half was ok.
'Cursed' Cheese Found In Egyptian Tomb Might Be The World's Oldest
Archaeologists reckon they've uncovered the world's oldest cheese in Egypt, maturing for more than 3000 years in an ancient tomb . In one of the broken jars, researchers found a "solidified, whitish" mass, wrapped in a piece of canvas, researchers said.
"We know this team are probably going to take possession off us, and we must be ready to work all together off the ball, and show solidarity and great effort", he said.