The runaway leaders lost for the first time, another unbeaten record was salvaged and Diego Costa soured a fiery London derby as the Premier League served up another Saturday of superb action.
There were 15 goals in total, including this fine control and strike on full debut from Manchester City’s £55m signing – [fee reported by BBC Sport] – Kevin de Bruyne against West Ham United at Eastlands.
But the Belgian’s first goal in English football was in a losing cause as earlier strikes from Victor Moses and Diafra Sakho earned the Hammers another brilliant away win and ended City’s 100% start.
Slaven Bilic’s side have now beaten Arsenal, Liverpool and the Citizens on the road this season.
Chelsea will have been relieved to see City’s bandwagon stopped and may consider themselves firmly back in the title race after a controversial 2-0 victory over Arsenal at Stamford Bridge.
Gabriel Paulista and Santi Cazorla were sent off for the Gunners while Diego Costa somehow avoided a red card for several offences. Kurt Zouma and Eden Hazard goals earned Chelsea a first win in three.
SEE MORE: Gabriel Paulista red card video – Watch Arsenal defender’s tussle with Chelsea’s Diego Costa
The champions are still eight points behind City, whose lead could have been cut to one by Leicester City had Claudio Ranieri’s surprise package beaten struggling Stoke City at the Britannia Stadium.
The Potters looked on course for their first win of the season after goals from Bojan, on his first league start in eight months, and Jonathan Walters, but the Foxes came from two down in successive games to earn a 2-2 draw as in-form attackers Riyad Mahrez and Jamie Vardy rescued Leicester a point.
Sunderland and Newcastle United are the only teams below Stoke in the table, and both North-East clubs lost to newly-promoted sides as Bournemouth and Watford picked up impressive wins.
Two goals in the opening 10 minutes earned Bournemouth a 2-0 win over the Black Cats, who had Younes Kaboul sent off, while an Odion Ighalo put down Newcastle despite Daryl Janmaat’s reply.
Aston Villa are just outside of the relegation zone following a 1-0 derby defeat to West Bromwich Albion. Saido Berahino, who threatened to go on strike after failing to get his desired move to Tottenham Hotspur, as The Independent reports, made friends with the Baggies fans again with the winner.
Elsewhere, Kevin Mirallas was sent off for jumping in on Modou Barrow in added time – only minutes after his introduction – as Swansea City and Everton played out a 0-0 draw at the Liberty Stadium.
Referee Stuart Atwell was justified in his decision to send off the winger, but Arsenal fans may be wondering how both Gabriel and Mirallas have seen red and Costa has escaped unpunished.
Both Garry Monk and Roberto Martinez may be disappointed with a point. The Toffees would have wanted to build on their toppling of Chelsea last weekend, but are still finding consistency a problem.
Meanwhile Swansea will have been looking to bounce back from defeat to Watford, but failed to find the net for a second straight game. They are still sitting pretty in eighth after a promising start.
Chelsea 2-0 Arsenal: Watch Kurt Zouma’s down nine-man Gunners with headed winner
Bojan goal video: Stoke magician scores on first start in eight months against high-flying Leicester
Victor Moses goal video: City shocked by piledriver as Chelsea outcast boosts parent club’s title bid
Results in full
Chelsea 2-0 Arsenal
Aston Villa 0-1 West Brom
Bournemouth 2-0 Sunderland
Newcastle 1-2 Watford
Stoke 2-2 Leicester
Swansea 0-0 Everton
Man City 1-2 West Ham