If Manchester United had any illusions that they were unbeatable this season, then Huddersfield gave them a reminder that they certainly are not.
David Wagner's side inflicted a shock 2-1 defeat on the Red Devils, with Jose Mourinho already under fire for his tactics in the goalless draw at Liverpool.
Top scorer Romelu Lukaku was somewhat off the boil again, while Victor Lindelof had a game to forget at the back.
However, there isn't a team on earth who doesn't have bad days at the office.
For the first time since Sir Alex Ferguson's retirement, Mourinho has finally assembled a team who look like genuine title contenders.
As it stands, Manchester City have to be the favourites thanks to their five-point lead, but Pep Guardiola will no doubt be looking over his shoulder at joint-second United and Tottenham.
Mourinho guided the club to two trophies in his first season - though he'll tell you it was three, including the Community Shield - so it's no wonder the likes of Ed Woodward are keen for him to continue his project.
The Portuguese boss isn't generally one for building a dynasty with one particular side; he spent two years at Porto, three in his first spell at Chelsea, two with Inter Milan, and three with Real Madrid.
PSG are interested
United are hoping they can buck that trend amid rumours that PSG could be his next destination.
According to Goal, the 20-time champions are planning to offer him a £250,000-a-week contract to tie him down for the next five years, as it's claimed the Parisians' interest is very much concrete and they could even make an approach in the relatively near future.
The Special One fuelled speculation linking him with a move to Ligue 1 by confirming on French TV that he doesn't plan to retire at Old Trafford.
He has since clarified those comments by telling a press conference:
“The answer is that nothing is happening; I am not signing a new five-year contract and I am not leaving for PSG. I have a contract and that is it."
United's latest offer is pretty eye-watering, so it will be interesting to see how he responds.
Unai Emery is yet to convince at the Parc des Princes, losing out on the title to Monaco last season and crashing out of the Champions League to Barcelona after winning the first leg 4-0.
Should Mourinho take the PSG job one day? Have your say in the comments.