Manchester City opened up a 12-point gap on Manchester United just 12 games into the Premier League season and returned to the top of the table with a convincing 3-1 win in Sunday's derby at the Etihad.

Early goals in each half from David Silva and Sergio Aguero put City in command and Ilkay Gundogan condemned United to a fourth league defeat of the season after Anthony Martial's penalty had given the visitors hope.

City leapfrog Liverpool to move back two points clear at the top of the table, while United remain in eighth.

The English champions have now won 11 and drawn one of their last 12 games with the only blip in that run coming in a creditable 0-0 draw away to Liverpool -- one of only two fixtures they lost in the Premier League last season.

The other was at home to United when City spurned the chance to seal the title against their local rivals by blowing a 2-0 half-time lead to lose 3-2.

City settled that score and ensured that if they are to be denied in their quest to be the first side in a decade to retain the Premier League, the challenge is likely to come from Liverpool or London rather than across Manchester.

Pre-match United were being offered at the longest odds they ever have for a Premier League match by bookmakers and their chances suffered another blow when Paul Pogba was ruled out by injury.

Despite an upturn in results in recent weeks to dampen speculation surrounding Jose Mourinho's future, United have still continuously started slowly and were again punished early on.

Bernardo Silva sent a warning shot flying just wide of David de Gea's goal before the opener arrived on 12 minutes as City's two Silvas combined.

Bernardo was the provider for his namesake to register his seventh goal of the season with a shot that had just too much power for De Gea.

City enjoyed upwards of 80 percent possession in the opening 20 minutes as the visitors struggled to gain any sort of foothold in the game.

But United did at least stem City's flow as the half wore on and the hosts didn't threaten again until Aguero fired into the side-netting just before half-time.

Handed a slightly better angle three minutes after the break, the Argentine made no mistake as he played a one-two with Riyad Mahrez and blasted high past De Gea to move out on his own as the Premier League's top scorer with eight goals.

Yet, just as City threatened to run riot as they have done so often already this season, their momentum was halted when with his first involvement since coming on as a substitute Romelu Lukaku was upended by Ederson for a United penalty.

Martial kept his cool to slot home for the fifth straight league game and give United belief another great escape was possible.

Mourinho's men came from behind to beat Newcastle, Bournemouth and Juventus in the past month and the Portuguese also summoned Juan Mata and Alexis Sanchez from the bench in the hope of another late show.

However, it was City who still looked the more likely to score in the final quarter and sealed all three points in a style Pep Guardiola will admire.

Gundogan finished off a 44-pass move that dragged United all over the pitch before the German international controlled Bernardo Silva's cross to slot home five minutes from time.