Crystal Palace went into their game with Chelsea having not scored in 731 minutes but Cesar Azpilicueta's own goal sparked what would be a disastrous day for the champions.
Wilfred Zaha caused nightmares for a Chelsea side who were out-battled in midfield all afternoon in the absence of their star man, N'Golo Kante. Palace deservedly got their first win of the season but few would have seen it coming against this standard of opposition.
Chelsea's defenders went from among the best in the league to mediocre without Kante protecting them. David Luiz, Gary Cahill and Azpilicueta are reliable and experienced but were consistently overrun.
Conte highlighted the importance of Kante's contribution, as he faces another scan this week to reassess the length of his recovery period.
"To lose a player like Kante is not simple because he's able to cover a lot of the pitch," Conte said at Selhurst Park. "But, for sure, I have to think also to take into consideration a solution.
"You know very well that the balance is very important if you want to win. The balance is very important. For sure, today, our balance was poor. Yes.”
Tiemoue Bakayoko scored but he couldn't replicate Kante's controlling presence both on and off the ball. Cesc Fabregas is a different player entirely but Chelsea's outfield players were all below their usual high standards.
Michy Batshuayi was hauled off in the 57th minute for Pedro after a toothless display where he managed only 19 touches and didn't get a shot away. Last season it was Diego Costa who scored the winner here in a winter battle at a hostile Selhurst Park, while Alvaro Morata had netted 50% of Chelsea's league goals this term ahead of the match.
Batshuayi failed to win Conte over in his first away league start of his Chelsea career and he may have to wait a while longer to get another one.
Morata will remain Chelsea's main striker and one positive for Conte is that the £60 million man will return against Roma in mid-week.
Victor Moses' hamstring injury will make life harder for Conte, who needs to bring back some stability into his line-up.
Willian is starting to face criticism as an individual but Chelsea's real problems are as a team. The club isn't at the level right now of Manchester City who, having defeated Chelsea at Stamford Bridge a fortnight ago, blew Stoke City away 7-2 on Saturday.
Manchester United's point away to Liverpool now looks even better alongside Chelsea's result and Conte's men face a tougher challenge to be champions this season.
Back-to-back defeats at the start of last season forced Conte to change his system to a 3-4-3. And the Blues may need another 13 game winning run this time around if they are to overhaul the Manchester clubs.
Most importantly, though, he needs to get Morata and Kante back from injury.