Frank Lampard believes Chelsea have demonstrated they are on track to close the gap to Manchester City and Liverpool in the Premier League.
Chelsea opened the scoring against City on Saturday, but the defending champions - who are nine points shy of current leaders Liverpool - came back to win 2-1.
The defeat ends a six-match winning run for fourth-placed Chelsea in the league, though Lampard has no doubt his side demonstrated they have enough quality to challenge the leading teams in the competition.
"Some big parts were good, some bits we can improve on. That's why there's a gap, that's why there was a gap last year of however many points, that's what City and Liverpool have done," Lampard told Sky Sports.
"I think we went toe to toe in the main. A moment of quality from Mahrez and a deflection for the first goal feels like the difference, for me.
"There was a lot of detail in the game, but I feel like we didn't have that bit of quality that we can have. Games like this can be won or lost in the boxes - and I think it was [the case].
"We're coming to close the gap. I don't want to shout that too loudly because football is day to day, week to week.
"Now we have to show our response to a defeat after a great run of wins, it feels like a long time since we lost a game in the league, so now we need to go and straight away get back on it, because I do feel like there were bits of that game that show that we're coming.
"Of course we're in the early stages, we're three or four months in, we're a team that we're strong last year anyway but some of our players were playing in the Championship last season and there's a bit of a transitional feel to it.
"I feel if we keep working then we will be coming."
City won despite posting a possession figure of 46.74 per cent, according to official Opta data, the lowest figure any Guardiola side has registered in 381 top-flight games.
"It's how we try and play. You can never be comfortable, they had a few good opportunities early on, but so did we," Lampard added of his team's style.
"I think maybe we got a little bit sloppy in fact, gave them a chance. Good teams, great teams, work to earn their luck. We're in that process. We need to work to make sure that goes in our favour.
"I felt for big parts of the game, in terms of possession we had more and caused a lot of problems behind their midfield line, but then there were times when we were sloppy trying to pass it between our centre-halves, trying to get our full-backs involved.
"They pressed well, they're very well organised. They made it hard for us and there's details in our own game to push a bit more."