Southampton beat Premier League leaders Everton 2-0 at St Mary's Stadium on Sunday as Carlo Ancelotti's side became the final club to lose a game this season.
Southampton took the lead in the 27th minute when James Ward-Prowse played a neat one-two with Danny Ings, who provided the through ball for his fellow Englishman to fire a shot past Jordan Pickford.
Ings turned provider again eight minutes later when he crossed from the left flank to find Che Adams at the far post and the unmarked striker took his time to pick his spot to beat Pickford with a strike that deflected off Gylfi Sigurdsson.
With about 20 minutes to go, Everton were reduced to 10 men when defender Lucas Digne was sent off for a straight red card after he fouled Kyle Walker-Peters and Ancelotti could not bring on another defender having already made three substitutions.
Ancelotti confirmed Everton would appeal the decision but said Pickford escaping punishment for a potential season-ending tackle on Liverpool's Virgil van Dijk may have influenced the decision to punish them.
"The red card was a joke, it was not intentional. Maybe it was a yellow, for sure it was not violent conduct," Ancelotti said.
"Maybe all this talk all week against Pickford, against Richarlison (who was sent off against Liverpool), affected the decision and if so it's not right, it's not fair."
Everton remain top of the standings with 13 points and a healthier goal difference than city rivals Liverpool while Southampton moved up to fifth.
Ancelotti also fired a stark warning to his squad with tough fixtures on the horizon.
"I told the players winter is coming and we will have to react," he added