Chelsea extended its Premier League lead with an emphatic 4-1 victory over Norwich, and defending champion Manchester City climbed to second place by comprehensively beating Sunderland 3-0 on Saturday.

Chelsea fought back quickly after Grant Holt's opener for Norwich in the 11th minute, with Fernando Torres, Frank Lampard and Eden Hazard scoring before the break.

Branislav Ivanovic fired in a late fourth as Chelsea went four points ahead at the top of the league in its best start since the 2005-06 season.

City won through goals from Aleksandar Kolarov, Sergio Aguero and James Milner, while Arsenal is fifth after coming from behind to win 3-1 at West Ham.

Everton slipped to third after being held to a 2-2 draw by Wigan, West Bromwich Albion maintained its strong start with a 3-2 victory over bottom-place Queens Park Rangers, and Swansea recovered from two goals down to draw 2-2 with Reading, while Arsenal was at West Ham in the late game.

Chelsea's victory was overshadowed by the lingering fallout from John Terry's racism case, a year after he racially abused Queens Park Rangers defender Anton Ferdinand.

Defender Ashley Cole inflamed the situation on Friday when he responded to criticism of his evidence in Terry's judgment by blasting the Football Association with an obscene Twitter posting. Chelsea is now set to fine Cole after launching disciplinary action over the tweet.

On the pitch, as Chelsea fans chanted support for Terry and Cole, the team fell behind when Grant Holt beat goalkeeper Petr Cech after 11 minutes.

Ripping through defence

Fernando Torres ensured the lead only lasted three minutes by heading in the equalizer, before Chelsea steamrollered the winless visitors with Frank Lampard volleying the leaders in front.

Juan Mata then ripped through the Norwich defence and slipped the ball through for Hazard to put Chelsea further ahead before halftime, while Branislav Ivanvoic volleyed in a late fourth.

"We concentrate on our strength, and we try to win games with the players that we have and with a football philosophy that we're aiming to play," Chelsea manager Roberto Di Matteo said. "At the moment, the team is in healthy form. We are creating lots of chances, we are scoring lots of goals, and with different goal scorers as well. We don't rely on just one player, so it's a team that is in good shape."

City was also rampant against Sunderland, but had only three goals to show for the dominance.

Aleksandar Kolarov scored from a free kick after five minutes at Etihad Stadium, substitute Sergio Aguero added a second on the hour, and James Milner blasted another dead ball into the net.

It was City's first game this season without conceding a goal.

"We are disappointed defensively this season but we are happy with the clean sheet," City manager Roberto Mancini said. "We are looking strong now, and since we have come back off the international break we have been playing well."

Arsenal bounced back from Chelsea ending its unbeaten start last weekend despite falling behind to Mohamed Diame's opener for West Ham.

Oliver Giroud levelled from close range before halftime — the France striker's first goal in the league since arriving from Montpellier in the off-season.

"I'm so happy to score my first goal," he said. "Everyone was talking about this goal, saying: 'Don't worry, we trust you, keep going, concentrate'. I stayed confident."

And Giroud released Theo Walcott to run into the penalty area and put Arsenal in front with a low shot. Santi Cazorla's long-range strike made certain of the win.

"He's come in to the Premier League and taken it by storm — he's our conductor," Walcott said of Cazorla.

Everton dropped to third after relying on Leighton Baines' late penalty to earn a point.

Arouna Kone put Wigan ahead after 10 minutes, but Nikica Jelavic headed Everton level less than a minute later. Franco Di Santo restored Wigan's lead in the 23rd, which lasted until Kevin Mirallas was pulled down by Maynor Figueroa for Baines to equalize.

West Brom is level on points with Everton, behind only on goal difference in fourth. Goals from James Morrison, Zoltan Gera and Youssouf Mulumbu secured the win that will add to the pressure on QPR manager Mark Hughes with his team bottom despite an off-season spending spree.

Reading is out of the drop zone but only a point ahead of QPR after first-half goals by Pavel Pogrebnyak and Noel Hunt were wiped out by Miguel Michu and Wayne Routledge in Swansea's stirring comeback to clinch a point.