Joao Cancelo, Phil Foden and Riyad Mahrez all netted for Pep Guardiola’s side before Haaland added his customary goal to seal yet another one-sided success at the Etihad Stadium.

Haaland has scored an astonishing 20 goals in his first 12 competitive games since his £51 million ($56 million) move from Borussia Dortmund.

Fuelled by the Norway striker, City are the first club to score at least three goals in nine consecutive top-flight home matches since Wolves in 1959.

The champions are now two points clear of second placed Arsenal ahead of the north London club’s clash with Liverpool on Sunday.

Guardiola’s remarkable team have only lost one of their last 37 league games as they chase a fifth English title in the last six seasons.

City have scored 24 goals in their last six games, winning eight of their last nine games across all competitions.

In stark contrast to City’s blistering form, Southampton’s fifth successive defeat added to the mounting pressure on boss Ralph Hasenhuttl.

City opened the scoring in the 20th minute as Joao Cancelo weaved through the Southampton defence, evaded James Ward-Prowse’s challenge and fired through the legs of keeper Gavin Bazunu.

Phil Foden doubled City’s lead as he ran onto Kevin De Bruyne’s pass and clipped a deft lob over Bazunu into the far corner after 32 minutes.

Riyad Mahrez put the result beyond doubt in the 49th minute, the Algeria winger meeting Rodri’s cross with a clinical volley from a tight angle.

Inevitably, Haaland wasn’t to be denied and he finished off Cancelo’s pass with a typically ruthless close-range effort in the 65th minute.

At Stamford Bridge, Chelsea racked up a third win in new boss Graham Potter’s four games since replacing the sacked Thomas Tuchel.

Potter made seven changes after the midweek Champions League victory over AC Milan, with Reece James, Raheem Sterling and Pierre-Emerick Aubameyang among those rested.

Slick Chelsea

Showing the depth of their squad, Chelsea took the lead when Kai Havertz netted three minutes into first half stoppage-time with a looping header from Mason Mount’s pin-point cross.

Christian Pulisic put Chelsea in complete control with a cute finish after exchanging passes with Mount in the 54th minute.

Armando Broja grabbed his first goal for Chelsea with a 20-yard drive in the 90th minute.

After their spluttering form at the end of Tuchel’s reign, Chelsea are up to fourth place, although Brighton would go back above them with a win against Tottenham in Saturday’s late game.

Managerless Wolves, who sacked Bruno Lage earlier in the week, remain in the relegation zone after a third successive defeat.

Bournemouth put under-fire Leicester boss Brendan Rodgers back on the hot seat with a 2-1 win at Dean Court.

Second bottom Leicester took the lead in the 10th minute when Patson Daka slotted hom.

But Bournemouth equalised in the 67th minute through Philip Billing, who volleyed into the roof of the net following a mistake from Wout Faes.

And Ryan Christie completed Bournemouth’s comeback in the 71st minute with a close-range finish after Dominic Solanke flicked on Billing’s cross.

Having won for the first time this season on Monday, Leicester have lost seven of their last eight games.

Fifth placed Newcastle thrashed Brentford 5-1 at St James’ Park.

Eddie Howe’s men went ahead after 22 minutes when Bruno Guimaraes headed in from Kieran Trippier’s cross.

Six minutes later, Callum Wilson crossed for Jacob Murphy to tap into the empty net.

Ivan Toney reduced the deficit with a 54th minute penalty awarded for a handball by Dan Burn, but Guimaraes’ long-range blast restored Newcastle’s two-goal advantage two minutes later.

Miguel Almiron struck in the 81st minute and Ethan Pinnock’s 90th minute own goal completed Brentford’s dismal day.