LONDON (AP) -Manchester United was toppled from the Premier League summit by Manchester City on Saturday after losing to Norwich, while its crosstown rival routed Aston Villa to top the standings for the first time this season.
United's third loss of the season was inflicted by former youth team player Anthony Pilkington, whose second-half header gave Norwich a 1-0 win.
Defending champion City moved a point ahead of United after recording the biggest win of the season, beating Villa 5-0 as Sergio Aguero and Carlos Tevez each scored twice after David Silva's opener.
In a day of a drama, third-place Chelsea lost 2-1 as manager Roberto Di Matteo returned to former club West Bromwich Albion, which moved a point behind the European champions.
And in the north London derby, Arsenal came from behind to beat Tottenham 5-2 after Emmanuel Adebayor's sending off swung the game in his former team's favor.
The pressure increased on Queens Park Rangers manager Mark Hughes after his winless side lost 3-1 to Southampton to stay bottom. But Reading secured its first win, beating Everton 2-1, while Luis Suarez scored twice in Liverpool's 3-0 win over Wigan and Swansea won 2-1 at Newcastle.
At Carrow Road, it was a lackluster display from United, which was without striker Wayne Rooney because of tonsillitis. Norwich secured its third win in five league matches when Pilkington headed in Wes Hoolahan's cross on the hour.
"You've got to give credit to the way Norwich defended - they defended for their lives tonight," United manager Alex Ferguson said. "The only chances we had were half chances."
City remains the only unbeaten team and finally looked like title contenders again on Saturday.
"In the last two games I think we changed something. In our mind we found a good spirit, like last year," City manager Roberto Mancini said. "For us it is very important we start to play well and in the last two games we have scored six goals with our strikers. I think we have been missing their goals."
But City took until the 43rd minute to take the lead, with Silva tucking the ball into the net from close range after Villa failed to deal with Samir Nasri's corner.
"In the first half we played well, created a lot of chances, but we were too soft when we had chances to score," Mancini said.
City was far more ruthless after the break, with Aguero netting from the spot in the 54th after Andreas Weimann handled.
City was awarded another penalty 10 minutes later when Barry Bannan handled and Tevez converted his spot kick.
Aguero was on target again, with the Argentina striker scoring from a tight angle after bursting into the penalty area.
Tevez completed the rout by grabbing his second, tapping in from close range after being picked out by Nasri. The result plunged Villa into the relegation zone.
Chelsea had been in control of the Premier League in the opening weeks but has slipped to third and is on a four-game winless run.
Shane Long put West Brom in front a day after his grandmother died and revealed an "RIP Nan" t-shirt after heading in James Morrison's cross in the 10th.
Eden Hazard leveled before halftime, heading in his fourth goal of the season, but Peter Odemwingie nodded in West Brom's winner after the break from Long's cross.
At Emirates Stadium, Adebayor put Tottenham in front after 10 minutes but was sent off eight minutes later for a high challenge on Santi Cazorla.
Per Mertesacker started Arsenal's comeback with a 24th-minute header, and Lukas Podolski and Olivier Giroud both found the net before halftime.
Cazorla swept in the fourth goal on the hour before Gareth Bale reduced the deficit for Tottenham, but Theo Walcott knocked in the fifth in stoppage time to give Arsenal a lift after its worst start to a season since during Wenger's 16-year reign.
A third successive league loss for Spurs allowed Arsenal to move above Tottenham into sixth.
Everton dropped to fifth after losing at Reading despite Steven Naismith putting the Merseyside club in front.
Adam Le Fondre headed Reading level in the second half and then netted the winner from the spot after being fouled by Seamus Coleman. The victory moved Reading up to 17th place with nine points and out of the relegation zone on goal difference.
Southampton remains in the drop zone but moved four points above QPR by extended the London club's winless run to 12 matches.
Rickie Lambert, Jason Puncheon scored for Southampton and after Junior Hoilett pulled one back, QPR defender Anton Ferdinand scored a late own goal.
Liverpool rose to 11th place after Suarez scored twice in nine second-half minutes and then played a part in the third which saw Jose Enrique score his first goal for Brendan Rodgers' side.
In another mid-table meeting, Swansea won at Newcastle for the first time since 1980, with goals from Miguel Michu and Jonathan de Guzman securing a 2-1 win. Demba Ba scored a consolation goal in stoppage time.