For a moment, it seemed Roberto De Zerbi had made a mistake in his press conference after this thunderous afternoon at the Amex.

We should have known better.

Albion’s current head coach hardly put a foot wrong all day as side beat Chelsea 4-1.

Eight weeks (minus one day) after seeing Graham Potter’s side smash Leicester 5-2, Albion fans enjoyed the thrills of goals and a win again.

They were eight turbulent weeks (minus one day) since Potter had turned to the West Stand, arms aloft, to join their celebrations of Alexis Mac Allister’s majestic free-kick with almost the last kick.

All seemed well with the Albion world on that Sunday afternoon.

Little were we to know what was to follow three days later (although one wonders whether some at Stamford Bridge already had an inkling).

So why did De Zerbi say eight tough months as he started an answer to reporters?

You mean weeks, Roberto. Easy mistake to make in a foreign language.

Then, as he continued, all became clear – as did just what this opportunity at the Amex means to him and his staff.

With reference to his time at Shakhtar Donetsk, which was cut short by war, he said: “Today I am very happy for myself, for my staff because we have been through eight really tough months.

“I had already a team, a great team that Putin decided to take away from me.

“In this moment I have found another team. I have to be thankful with the players of Brighton, with the club, how they have welcomed me and how I have felt straight away since the first moment that they trust me.

“To find again a family, an atmosphere that is letting you feel like part of the environment, it’s something very nice and I have to be very thankful to Brighton.”

There’s some perspective for you.

But what happens on the pitch, and off it, at your football club still matters.

The most important of the unimportant things, as they say.

On Saturday, eight weeks (minus one day) later, Albion turned a page.

The De Zerbi tenure, which stumbled out of the starting blocks in terms of wins due to good play not being turned into goals, is now well and truly up and running.

With a first win for the new boss, a first league win for the club over Chelsea, the first goals under De Zerbi at the Amex.

And a landmark occasion for fans and players alike.

There have been smoother baton handovers, admittedly.

But, on Saturday evening, it felt like they had taken a huge step.

Potter and his staff, including Marc Cucurella, were given a torrid welcome and were played off the park.

Or, if you want to be precise, Chelsea and the way they have bought a lot of Albion’s hard work off the peg – at a price, of course – were booed, with Potter and colleagues the vehicle for that.

They were then buried by goals from two of Potter’s former players and two of his current team.

Surely no one denies how he took Albion from fourth bottom to fourth top.

Four just happened to be the magic number again when he returned.

He might have had an inkling of what could be coming.

We saw it under his command late last season.

That was when his Albion side were playing good stuff without getting wins. Not at home, anyway.

It felt like someone was going to get a hammering.

Then a fragile Manchester United came south and everything fell into place.

This was similar – except the damage was done earlier in the game and Chelsea now are better than United were then.

It was nicely set up for a home win but that did not mean the script would be followed. Football does not always work like that.

De Zerbi, who did not even know his line-up until the day of the game, used Leandro Trossard as centre-forward, got attacking width from the recalled Pervis Estupinan and did something Potter himself had trialled , putting Pascal Gross at right-back or wing-back, depending on your reading of it.

Team and crowd pressed with a vigour and force which brought back memories of a play-off against Sheffield Wednesday, long since held up as the night Albion and their crowd started a game in such a whirlwind manner.

But this time, after two goal-line clearances by Thiago Silva, they got the early goal as Kaoru Mitoma’s clever pass released Trossard to show off dancing feet, a cool head and precise finish.

Bedlam. Absolute bedlam.

Where would the goals come from apart from Trossard?

That which doubled the lead bore some resemblance to Lewis Dunk’s on that night against Wednesday.

But this time it was by Ruben Loftus-Cheek who kneed into his own net from a Solly March set-piece.

Robert Sanchez produced two super saves from Conor Gallagher before Trevor Chalobah prodded into his own goal when trying to prevent Estupinan’s low cross reaching Mitoma.

Chelsea changed things at half-time and got the early goal they needed as Kai Havertz, their most dangerous player, headed home a Gallagher cross.

That was the time when it might have gone wrong for an Albion side who did not appear to have great depth on their bench.

But they stood firm, Sanchez made two more saves and the presence and running of Julio Enciso gave them an injection when they needed it.

It was his shot, then follow-up when he might have passed, which led to Gross rounding things off in added time.

The Amex crowd erupted again.

It was an afternoon which meant so much to so many – for different reasons, as it turned out.

Albion: Sanchez; Gross, Dunk, Webster, Estupinan; March, Mac Allister, Caicedo; Lallana (Encisco 64), Mitoma (Lamptey 71); Trossard (Sarmiento 87). Subs not used: Steele, Undav, Gilmour, Turns, Furlong, Moran.

Goals: Trossard 5, Loftus-Cheek OG 14, Chalobah OG 42, Gross 90+2.

Booked: Encisco (83) foul.

Chelsea: Kepa (Mendy 46); Chalobah, Thiago Silva, Cucurella (Chilwell 63); Pulisic (Broja 78), Loftus-Cheek, Kovacic, Sterling (Aubameyang 63); Mount, Gallagher (Ziyech 78), Havertz. Subs not used: Jorginho, Zakaria, Azpilicueta, Hutchinson.

Goal: Havertz 48 Booked: Kovacic (11) foul, Sterling (50) foul.

Referee: Andrew Madley.

Attendance: 31,746