If Everton's improvement could be embodied by just one player on the pitch, you'd have to choose Morgan Schneiderlin.
His career in royal blue so far has been a rollercoaster of differing form, his flashes of quality just making his inconsistencies since arriving in January 2017 all the more frustrating.
But, Duncan Ferguson put a show of faith in the Frenchman for this match, which was repaid in some style.
One of the main criticisms levelled at the Blues in what was a true debacle at Anfield in midweek was how exposed the midfield found themselves.
The temporary boss not only changed the system to try and combat that fact, switching back to a more natural four-man defence, but also altered the personnel to bring Schneiderlin into the fold in place of Tom Davies.
That raised some eyebrows from a few fans before kick off. Would the Frenchman and Gylfi Sigurdsson have the legs to cope with what this young and vibrant Chelsea side were set to throw at them?
Yes, was emphatically the answer.
Some have questioned the effort levels of the 30-year-old during his time at Goodison Park but that criticism couldn't be levelled at him this time around.
This was arguably the best Evertonians will have seen Schneiderlin play in a long time, perhaps since his first few months on Merseyside.
The midfielder was clearly eager to repay his manager and drag the Blues to victory. He was tough in the tackle, he was full of running, he was closing Chelsea down, he was getting the hosts on the front foot and further up the pitch.
One moment in the first half in particular really set the tone for Schneiderlin as he harried Chelsea right back into the own half before forcing them out of play.
This was no doubt a huge improvement from the Frenchman, and long may this kind of display continue in the near future.
Who said that 4-4-2 was old fashioned?
Even if it is a system of a time gone by on a regular basis, Everton's display on Saturday showed just how useful it really can still be.
Everyone knew the Blues couldn't play five-at-the-back again this time around, even if Yerry Mina had been deemed fit to start this game.
Over the weeks and months leading up to the sacking of Marco Silva even, there were sporadic calls from some sections of the fanbase to go back to basics – stick two strikers up front, have two banks of four behind them and see what happens.
Ferguson on Friday spoke of a more simplistic approach to the game, but it may still have been a surprise to see a 4-4-2 to some.
Chelsea certainly seemed shocked by it, and they couldn't cope with Everton at all.
Dominic Calvert-Lewin and Richarlison deserve the utmost credit for their displays. They haven't been used as a strike pairing before, but this performance will just raise the question of why that hasn't been the case.
Both men were absolutely dogged in their attempts to keep the visitors on the back foot and not give their defenders, or holding midfielders for that matter, any extra inch to try and play themselves out of danger.
Working in tandem with each other it was no surprise to see both on the scoresheet, and it's something Blues supporters will be desperate to see more of in the future.
The gameplan became clear from Everton in the early stages. Keep Chelsea nervous at every opportunity, don't give them any space or time, and then be direct when attacking.
It was executed brilliantly in the end, with long balls down the flank to the likes of Alex Iwobi and Theo Walcott becoming key factors of the win.
It might not have been the most pretty of styles, in the long term it might not be the answer, but this was exactly what was needed on Saturday.
In a way, it tapped into the kind of qualities Everton were desperate to see. Fight, direct play, intensity, intelligence.
That was what Ferguson promised on Friday, and he made sure his side delivered.
What to take and where to go
The obvious question was aimed at Ferguson after the final whistle.
Surely, despite distancing himself from such thoughts in his pre-match press conference on Friday, he would want the job on a permanent basis after such a rousing display.
Again, though, his response was clear – he was here for this game, he appreciated the experience, and he is sure the Blues are looking for the best of the best.
Whoever the new manager is will have to watch closely at this performance from Everton, however. This was a blueprint to try and build from.
The passion from the supporters, first off, is an absolutely key factor. It's no coincidence that Ferguson got the crowd up for the match from the first whistle, only to see his side score in the opening five minutes.
That relationship between the fans and the squad was crucial at Goodison Park in that strong run towards the end of last season and that hasn't changed. The new manager will need to tap into that sense of belief in the stands.
Not only did Ferguson motivate the fans, but he got the players right up for this game as well.
This was a high-energy, dogged and passionate display if nothing else from the Blues. Those are all qualities Evertonians demand, but haven't seen enough of in recent months.
The new boss may well have a different style than the simplistic display of this match – different games will require that in the future, but the fight and willingness to scrap for every ball can't be substituted.
Ferguson was brought in to get a reaction for one game, to help the side in the fight they currently find themselves in, and he was successful.
Suddenly things look a little brighter for an incoming manager don't they?
This win ended a run of three straight defeats, took the Blues out of the relegation zone and up to 14 and positioned them right back in the mid-table mix – just a couple of wins away from sixth place.
And suddenly there is a squad here that's shown a mixture of fight, resilience and quality to beat one of the most impressive sides in the country.
If this is to be Ferguson's one and only match in temporary charge, he's done his job in some style – Farhad Moshiri and the rest of the Blues hierarchy should be lavishing praise on him.
With more big games against tough opponents on the horizon, things are starting to look just a little brighter at Goodison Park.
Duncan Ferguson deserves huge thanks for that.