Those who bemoaned the decision to sack Frank Lampard said all he needed was time. Thomas Tuchel required only one day to make a difference to Chelsea's style of play.
Six weeks on from his appointment, he has them back among the top four of the Premier League and looking like the best bet to compete with Manchester City in the long term.
Beating Liverpool at Anfield might not be the feat it once was but this was a supremely controlled performance by Chelsea and a deserved victory. Mason Mount's excellent goal in the first half had been coming. The equaliser never really looked like it was.
"Liverpool created very little throughout the 90 minutes," said Jamie Carragher on co-commentary for Sky Sports. Back in the studio, Ashley Cole was impressed too. "One of the best performances I have seen from Chelsea in terms of playing out from the back."
Tuchel himself was delighted.
"We needed to show courage if we wanted to escape the pressure and we did this excellently. We were strong in our transition game, we were strong in defending and winning second balls and counter-pressing. It was a very, very good team performance."
It was a key game in which to deliver it because Liverpool could have overtaken Chelsea with a victory. Everton and West Ham still can if they win their games in hand. On this evidence, Chelsea can chase down those above them rather than worry about those below.
There was never any denying the quality within this expensively assembled squad. As a result, it is tempting when watching Timo Werner wreak havoc with Liverpool's high line or N'Golo Kante snuffing out danger in midfield to suggest this revival was inevitable.
But Chelsea had lacked direction, having lost five of their previous eight Premier League games when Tuchel arrived. They were tenth in the table at the halfway stage of the season when he walked out at Stamford Bridge for his first game in charge.
The transformation has been remarkable.
This team was one in search of their own style, a distinctive identity. It emerged instantly as Chelsea broke their Premier League passing record in that first 45 minutes against Wolves. A new formation was introduced and has remained - bringing much-needed clarity too.
The team's defensive issues have been emphatically resolved. Not only are Chelsea unbeaten in their eight Premier League games under Tuchel - 10 in all competitions - but they have conceded only twice in that time. Suddenly, they look rock solid at the back.
A reminder that this record has been sustained despite the loss to injury of Chelsea's most experienced defender - and perhaps the player whom Tuchel knew best from their time together at Paris Saint-Germain - in Thiago Silva. They have barely skipped a beat.
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Andreas Christensen, a player many had dismissed as not good enough to succeed in a Chelsea shirt, has been a revelation in recent games. After completing all 73 of his passes against Manchester United at the weekend, he was even better against Liverpool.
The Dane's calm distribution has been important in helping Chelsea to maintain their passing game even when it was difficult. Liverpool are famed for their ability to win possession in the final third of the pitch but were unable to build any real pressure.
While the defensive platform has been established, the attacking pattern might take a little longer to perfect - there is more to come from this Chelsea team in the final third when flowing freely.
But fears that Mount's progress might be stifled by Lampard's exit, exacerbated when Tuchel omitted him from his first line-up, are already proving unfounded. Indeed, there are already reasons to believe that, playing in those pockets, his development will continue.
Werner did not get his goal at Anfield but he came close and supporters will appreciate the logic of his selection with even Jurgen Klopp noting that his compatriot had been included to expose Liverpool's high line. Perhaps Olivier Giroud will return to the starting line-up when Chelsea need to break down a deeper defence.
It makes sense.
Everything is beginning to make sense now and that is to Tuchel's huge credit. The decision to turn to him has already been vindicated.
He is making a difference.
Asked how he has down it so quickly, he preferred to put the emphasis on the efforts of those on the pitch.
"I do not know but I feel a big part of this club, actually, from the first moments. We put in a lot of effort and try to help. When the team shows their quality, it is a players' game."
It has become quickly apparent that those players were crying out for a coach like Thomas Tuchel.