Sadly, the Toffees were brought back down to earth with a bump as a flat performance on the south coast resulted in a deserved 2-0 win for the Saints - though they remain top on goal difference.
It was one of those says where everything that could go wrong, did go wrong, including a red card for Lucas Digne that will see him miss the next three games.
Everton were given a boost before kick-off when James Rodriguez was passed fit despite missing training during the week.
Unfortunately, the Colombian didn’t get a look in during the opening 45 minutes, though he wasn’t alone.
Everton’s best opportunity came when Gylfi Sigurdsson’s dipping long-range effort clipped off the top of the crossbar. That was it in an attacking sense in the first half, with Southampton regularly exposing the defence at the other end.
Oriel Romeu drew a smart stop from Jordan Pickford with a deflected long-range effort. Seconds later, the Saints were in front.
The Toffees were perhaps guilty of falling asleep from a throw-in which allowed Danny Ings to combine well with James Ward-Prowse, who powered an effort across Pickford and into the corner.
The home side’s second came down the opposite flank, Ings getting to the left byline and chipping in a cross that found Che Adams at the far post, the striker taking several touches before firing in an effort that deflected off Sigurdsson and beyond a stranded Pickford.
Ancelotti responded by bringing Bernard on for Iwobi at the break, and after it proved ineffective, brought on Anthony Gordon and Fabian Delph for Sigurdsson and Abdoulaye Doucoure 15 minutes into the second period in attempt to shake some life into the side.
Those changes did improve Everton slightly, but Southampton, with a 2-0 lead to sit on, defended deep and restricted the Toffees to only half chances, with the pacy Adams offering a threat on the counter.
The game was effectively over when Digne was sent off for a late challenge on Kyle Walker-Peters.
The Frenchman caught the defender’s Achilles from behind as he was chasing after the ball. It looked accidental to me, if painful, but referee Kevin Friend deemed it worthy of a straight red.
After the fuss this week about Pickford’s challenge on Virgil van Dijk, are we surprised a referee is quick to show a red card to an Everton player?
It would be harsh to be too hard on the players given the start they have made to this season, but this was perhaps a painful reality check as to the team’s ambitions this season.
The squad is looking stretched already, especially with Digne’s looming ban thrown into the mix. The sight of James limping through the final 15 minutes suggests he isn’t fully fit either.
The good news is they have a week to rest and recuperate ahead of a trip to the north east to take on Newcastle.
Unfortunately that is the only positive to take from what was a pretty rotten afternoon all round at St Mary’s.
Ancelotti has already spoken about not getting carried away with wins, or being too down about defeats - the first loss of the season was always going to come.
This is just an afternoon they need to learn from and move on.