If winning ugly truly is a mark of champions, Manchester City's Premier League title challenge is very much alive.

After losing to Liverpool two weeks ago and then watching yet another late winner from Jurgen Klopp's relentless Reds at Crystal Palace earlier on Saturday, City's task against Chelsea was straightforward: don't give the leaders any more reason to believe.

Pep Guardiola's message before the game was simple, too, as the task of hauling in Liverpool was laid bare: "We have two options – give up or don't give up." Against Chelsea, they flirted with the former before choosing the latter.

Quite what the message to Benjamin Mendy was is another matter, though, and one that could have deeper implications when the title race enters its more decisive months.

Chelsea, of course, came to Etihad Stadium in buoyant mood - quite the contrast to the way they left it last season after a 6-0 humiliation of a kind rarely experienced, certainly since Roman Abramovich laid down roots in London. But this is a different Chelsea: a team playing with few expectations, bursting with confidence and chasing an eighth away win in a row in all competitions for the first time.

More to the point, there was a plan: get after Mendy. Not included against Liverpool for "tactical reasons", Mendy was part of the Chelsea blueprint from the off. Willian attacked relentlessly down the right and N'Golo Kante often joined him. With Raheem Sterling unwilling to track back, Rodri was dragged to the left to provide cover.

That was how Chelsea struck.

Mateo Kovacic played a one-two with Jorginho on halfway, and Kante set off, a diminutive whirlwind surging through the middle of the sky blue shirts onto the Kovacic pass. Rodri, out of position, did not track him; Fernandinho, emergency centre-back again, could not. Kante finished well under pressure from Mendy, who had belatedly realised the danger. It was Chelsea's second and final shot on target.

Chelsea deserved their lead. Beating City requires a careful plan and the hope of an off-day from Guardiola's men and, boy, they had that in the first half-hour. Kante has not been transformed by Frank Lampard - nobody should forget how Maurizio Sarri was often pilloried for playing the France star further forward - but he has embraced this idea of unleashing the former Leicester City man. In terms of average positions, Kante ended the first half the furthest forward of any Chelsea player. He was a weapon deployed with astute precision.

City, meanwhile, were alarmingly poor. Whatever the end result, Guardiola teams can normally be guaranteed to have more possession and run that little bit harder than their opponents. After 45 minutes, they had had 45 per cent of the ball and been outsprinted 56-50.

And yet, they were winning.

Kevin De Bruyne was wayward with his early passing but it soon became clear that, if it was going to happen for City, it would happen through him. It duly did 29 minutes in, De Bruyne dummying Jorginho and finding the net via the well-placed studs of Kurt Zouma, all after Fernandinho waded back into more comfortable midfield waters to steal possession.

For all their own problems at left-back, City identified the same weakness in Chelsea, a team who, exciting as they are, have kept only three clean sheets in the league under Lampard. Emerson Palmieri was tasked with dealing with Riyad Mahrez and simply never managed it. When he asked for help from Kovacic, they were equally obliging in allowing Mahrez to cut into the box on his left foot and finish in supreme style.

Mahrez was the main threat after the break, a clever corner giving Joao Cancelo a chance to score before a brilliant Kepa Arrizabalaga save denied him a second goal of his own. He would have had a late assist for Sterling but for a correct VAR intervention for offside.

A Chelsea comeback never really looked on and City had control once Ilkay Gundogan was introduced, even if they ended with the lowest possession figure, 46.7 per cent, that Guardiola has seen in 381 league matches in charge of Barcelona, Bayern Munich and City.

They are back into third, nine points behind Liverpool, with a slight hop in their step if not quite a spring. Never mind the gap, as David Silva said on Friday; City have overturned them before.

But there is a nagging doubt about Mendy, about how he impacts the team as a whole and whether he is worth the gamble, that is more difficult to ignore.