Barcelona thrashed their greatest rivals 2-6 in a sensational goal-fest.
The Catalans are now certain to win La Liga as they now have a seven point lead over Real.
Lionel Messi and Thierry Henry netted twice each. Carles Puyol and Gerard Piqué got the others. Real Mardid's goals came from Gonzalo Higuaín and Sergio Ramos.
Chelsea will have taken note of the scoring exploits of Henry, Messi and the rest but will take heart from the fact they also let in a couple of goals.
The Blues beat neighbours Fulham 3-1 this afternoon.
Goals fron Nicolas Anelka, Florent Malouda and Didier Drogba gave the Blues bragging rights in West London tonight.
Sadly for Chelsea, Fulham are no Barcelona.
The Blues will have to start the game on the front foot and hopefully gain an early lead.
Barca will be confident of scoring at the Bridge, but Chelsea simply have to win the game.
Chelsea snuffed out Barcelona at the Camp Nou on Tuesday, the 0-0 scoreline reflected the first time Barcelona failed to score at home this season.
The winners will face either Manchester United or Arsenal. They will know who their opponents will before before they play as Arsenal will look to overturn United's 1-0 lead on Tuesday night at the Emirates Stadium. Chelsea and Barcelona play a day later.