Manchester City's aura of dominance took a significant blow on Saturday evening at Stamford Bridge.
Not many football fans gave Chelsea a chance, but Maurizio Sarri's side inflicted City's first Premier League defeat of the season, winning 2-0 and allowing Liverpool to take top spot.
N'Golo Kante gave the Blues a surprise lead on the stroke of half-time, before David Luiz sealed all three points with a deft header from a corner.
In the second-half, Chelsea were the far more threatening side, with the likes of Leroy Sane, Raheem Sterling and Riyad Mahrez struggling to have any impact.
At the back, City looked suspect as well, with Kyle Walker certainly not enjoying his best afternoon in a sky blue shirt.
And it seems those in the BT Sport studio were less than impressed with the right-back's performance.
One football fan posted some quite extraordinary footage of Rio Ferdinand and Joe Cole's off-air rant about Walker, picked up from a live stream.
Ferdinand can be heard saying, per Mirror: "Look at Kyle Walker, sleeping. Look at Kyle Walker.
"That's why England - whenever he plays - he'll always be a liability at the top level."
Cole then joins in, saying: "I'm with you, I'm not saying that though because his mate comes to the gym."
"Everyone talks about this Man City team being perfect, it's not perfect. They will gift you that. They will give you that quick attack because Kyle Walker is playing as a winger."
Ferdinand then adds: "You always know that you will get an opportunity against them, but you have to be clinical like they were today. If you've got the b*******."
Cole the concludes by saying: "And that's why the good teams can hurt them because they've got players like [Eden] Hazard."
You have to wonder why BT didn't broadcast a pretty eye-opening conversation about City and Walker's flaws.