Everton boss Ronald Koeman admitted he was stunned by Chelsea’s brilliant performance after his team were thrashed 5-0 at Stamford Bridge.
Eden Hazard scored twice as the Blues moved to the top of the Premier League in style.
Koeman said: “They showed us a high level of football. We did not expect that difference on the pitch, but that’s what happened.
“It is good for everyone to see how the best technical players play; how they work, how they run, how they press – it’s a big lesson for everybody what happened on the pitch today.”
Boss Antonio Conte’s preferred 3-4-3 system has emphatically brought the best out of Chelsea, who have won five league games in a row.
And Koeman believes they have shown they are serious title contenders.
He said: “I didn’t see Chelsea live (before today) – yes on television – but I think playing this system, winning five games in a row and not conceding, it is the best way for them and of course some of their players are showing the highest level of football.
“I have never seen a team as strong playing this system. It is very difficult to play against the movement of Pedro, Hazard and Costa.
“The manager has brought a winning mentality to the players and if they keep that they will fight for the tite for sure.”