2. Arsenal, 2007/2008
As Eduardo was carried off the pitch having suffered a horrific leg-break, you could feel something change in the Arsenal camp.
They went on to lose the lead, conceding an injury-time penalty before captain William Gallas refused to leave the pitch after the game.
The frustration, anger and disbelief on Gallas' face was a reflection of his team.
Topping the league in early March, the Gunners were set to end the years of talk about not winning trophies.
But that injury, that on-pitch protest and that game sent Arsenal into free-fall.
It was the closest Arsenal had or have come to winning the league since their Invincibles campaign.