Unexpected defeats for Chelsea and Manchester United allowed champions Manchester City to stroll into first place in the Premier League on Saturday by crushing Aston Villa 5-0.
United's 1-0 loss in the late kick-off at Norwich City prevented them from returning to the summit, while third-place Chelsea have now gone four games without a win after losing 2-1 at West Bromwich Albion.
David Silva's scrappy 43rd-minute goal put City ahead at the Etihad Stadium, before penalties from Sergio Aguero and Carlos Tevez -- awarded for handballs by Andreas Weimann and Barry Bannan -- made it 3-0.
Aguero beat Villa goalkeeper Brad Guzan at his near post to claim his second goal in the 67th minute and Tevez then tapped home the fifth, as City warmed up for Wednesday's vital Champions League encounter with Real Madrid in style.
"In the last two games, I think we changed something. In our mind we found a good spirit, like last year," said City coach Roberto Mancini, whose side beat Tottenham Hotspur 2-1 last weekend.
"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."
The result dropped Villa into the bottom three and took City a point above former leaders United, who slumped to their third defeat of the campaign at Carrow Road.
Javier Hernandez started up front for the visitors after inspiring last weekend's 3-2 win at Villa, but it was former United trainee Anthony Pilkington who claimed the game's only goal with an excellent 60th-minute header.
United's best chance of an equaliser saw Norwich goalkeeper John Ruddy produce a flying save to prevent Sebastien Bassong from scoring an injury-time own goal, as Chris Hughton's side held firm to claim another prized scalp after last month's 1-0 win at home to Arsenal.
Meanwhile, Chelsea's early-season momentum appears to have fizzled out completely after their defeat at coach Roberto Di Matteo's former club left them four points off the pace.
Shane Long put West Brom ahead at the Hawthorns with a 10th-minute header and then teed up Peter Odemwingie for what proved to be the winner after Eden Hazard's header drew the visitors level six minutes before half-time.
West Brom's victory allowed them to climb to within a point of Chelsea and they clambered over Everton into fourth place after David Moyes' side were beaten 2-1 at relegation-threatened Reading.
Steven Naismith punished sloppy defending to give Everton a 10th-minute lead but a second-half Adam Le Fondre double saw the Royals belatedly register their first win of the campaign.
In the battle of the basement clubs, Southampton won 3-1 at Queens Park Rangers to leave the London club four points adrift at the foot of the table and increase the pressure on coach Mark Hughes.
David Hoilett gave QPR hope when he pulled a goal back after Rickie Lambert and Jason Puncheon had put the Saints 2-0 up, but a late Anton Ferdinand own goal confirmed a win that took Nigel Adkins' men to within a point of safety.
Earlier, Tottenham striker Emmanuel Adebayor scored but was then sent off as his former club Arsenal stormed back from behind to win 5-2 in the north London derby at the Emirates Stadium.
Adebayor was sent off for an uncontrolled lunge at Santi Cazorla eight minutes after putting Spurs ahead, and goals from Per Mertesacker, Lukas Podolski, Olivier Giroud and Cazorla put Arsene Wenger's men in control.
Theo Walcott made it 5-2 after Gareth Bale reduced the arrears, to produce a repeat of the scoreline from last season's equivalent fixture in February.
"We showed people how good we are today," Walcott told Sky Sports television.
"It'll give us tremendous spirit, and we've got a lot of players back to fitness and everybody's very confident."
Elsewhere, in-form Luis Suarez took his tally for the season to 10 league goals with a brace as Liverpool beat Wigan Athletic 3-0.
Goals from Michu and Jonathan de Guzman saw Swansea City win 2-1 at Newcastle United, who replied in injury time through Demba Ba.