Chelsea manager Frank Lampard believes the gap between his side and Manchester City has narrowed dramatically in his first few months in charge despite City coming from behind to beat the Blues 2-1 at the Etihad on Saturday.
A first defeat in the Premier League since September sees Chelsea slip behind third-placed City in the table, but there was plenty of encouragement for Lampard on a ground where they were thrashed 6-0 last season.
City, who finished 26 points ahead of Chelsea last season, had the lowest percentage of possession ever recorded by a Pep Guardiola side in 381 league matches.
"Big parts (of the game) were good, some parts we can improve on, but that's why there is a gap to Man City and Liverpool," said Lampard.
"We're coming to close the gap, I don't want to shout that too loudly. Now we have to show a response after a great run of wins."
Liverpool's late win at Crystal Palace earlier in the day meant City started 12 points behind the leaders and looked in danger of failing to cut that gap when N'Golo Kante gave Chelsea a deserved lead midway through the first half.
However, Kevin De Bruyne's deflected strike breathed new life into Guardiola's men and a trademark left-footed finish from Riyad Mahrez saw City edge a thrilling encounter.
"They are an incredible team," said Guardiola in praise of Chelsea.
"Most of the teams at the top now, they have the courage to play. Liverpool, Leicester, our team, Chelsea, they want to play, to go forward.
"They are a top side, but we fought a lot and we had a good victory."
- City's injury worries -
A vital three points, however, was soured for City by more injury problems.
Rodrigo, David Silva and Sergio Aguero all had to be replaced in the second half with Guardiola particularly concerned about Aguero's availability ahead of the packed festive schedule.
"Hopefully we'll know tomorrow, but the first indication is not good. It's a muscular injury," added Guardiola on Aguero's fitness.
De Bruyne flashed a shot inches wide in a bright opening by the hosts as they sought to make amends for a 3-1 defeat by Liverpool in their last outing before the international break.
However, it was Chelsea who began to take control of the game in the first quarter.
Willian drilled wide at the end of a flowing counter-attack before Fikayo Tomori's effort after a corner ricocheted around the City box also flew just off target.
There was no surprise when the visitors eventually took the lead 21 minutes in when Kante made the sort of run from midfield that Lampard made his trademark during his playing career before slotting the ball under Ederson from Mateo Kovacic's wonderful pass.
City bemoaned their luck in defeat at Anfield a fortnight ago, but got the slice of fortune they needed to gain a foothold back in the game eight minutes later when De Bruyne's tame shot deflected off Kurt Zouma to leave Kepa Arrizabalaga wrong-footed.
Mahrez then turned the game on its head with a brilliant jinking run and finish into the far corner as City clicked into gear.
The champions should have been further ahead by the break as Kepa's poor clearance gifted possession to Aguero, but the Argentine hit the bar with just the keeper to beat.
In a game that flowed from end-to-end, City could never feel comfortable with a single-goal lead and Kante was close to his second when a goalbound shot was deflected behind by Fernandinho.
But City's margin of victory could also have been greater as Raheem Sterling found the bottom corner deep into stoppage time, only for VAR to rule the goal out for offside.