Chemsdine Talbi struck a dramatic stoppage-time winner as Sunderland stunned Chelsea with a 2-1 victory at Stamford Bridge.
The 20-year-old Morocco international strode unmarked into the box to sweep home after Brian Brobbey had held the ball up all on his own against two defenders, sparking delirious scenes amongst away supporters in the Shed End.
The game had been a fierce contest, but if Chelsea's ambitions extend to pushing on from last season's fourth-place finish then this is the kind of even fight they will need to learn how to edge.