Tottenham boss Andre Villas-Boas has questioned the importance of Chelsea's Champions League triumph. Tottenham boss AVB faces his former club tomorrow for the first time since they sacked him last season.
Chelsea went on to lift the Champions League trophy under Roberto Di Matteo.
But AVB - who took over at Spurs in the summer - lit the touchpaper for the London derby by insisting that achievement was easier than his 2011 Primera Liga triumph in Portugal, when his Porto side emulated Arsenal's Invincibles.
AVB said: "Winning any league is extremely difficult but going through it unbeaten is also extremely difficult.
"Which is more difficult - winning the Champions League or remaining unbeaten in the league?
"Remaining unbeaten in the league."