Chelsea host Tottenham on Wednesday in one of the most eagerly anticipated London derbies to grace the English Premier League.
A home win would all but secure a top-four spot and with it UEFA Champions League football, while it would also render Spurs' hopes of landing the very same thing dashed.
An away win would allow Andre Villas-Boas' charges to leapfrog Arsenal into fourth and pile the pressure on everyone around them.
Spurs have never won at Stamford Bridge in the Premier League era, but that won't deter them—they ended a dismal streak at Old Trafford earlier this season by winning 3-2, and this one's next on the list.
Let's take a look at the key battles that will decide this game.
Chelsea's full-backs vs. Gareth Bale
What position does this guy even play anymore? He pretty much drifts wherever he wants to, and his team reorganise accordingly.
It's become a joint effort to contain Bale, with full-backs trying to show him onto his "weaker" side while the holding midfield create a barrier to stop him from shooting.
Even then, he just loops one over the top á la West Ham.
Chelsea's hopes of a clean sheet and result rest on their ability to contain the Welshman.
Oscar vs. Benoit Assou-Ekotto
Many will be looking at Eden Hazard's (expected) return to the side and hope he catches fire once more. He will have a royal tussle with fellow speedster Kyle Walker, but Chelsea need to be looking at their right side as a genuine means of progress.
Assou-Ekotto is struggling for form and was torn apart by the movement of James Milner and Carlos Tevez at White Hart Lane. Oscar can do an incredibly similar thing.
BAE struggles to contain players who are not true wingers and often misses the chance to cut out intricate buildup play.
A touch of Bayern Munich's approach—where the striker drifts to the right and works the right-hand corner with the winger and No. 10—could see Juan Mata and Oscar really prosper in terms of chances created.
Jermain Defoe vs. Chelsea's Defence
Two starts for Defoe, two rather average games.
But that's not enough to bring the dreaded Emmanuel Adebayor back into the lineup, who, quite frankly, looks like he wanders onto football pitches by accident these days.
Defoe has come back from a long layoff and the expectation placed upon him is unbelievable, but now more than ever Spurs fans need him to step up and deliver.
You're never awarded a plethora of chances at Stamford Bridge, so Defoe needs to be at his clinical best.