The last remaining English side in the Champions League shocked the tournament favourites and will take a 1-0 lead into next week's second leg after an impressive display of clinical finishing and dogged defending. The Spanish side are now odds-against at 11/10 (2.10) for victory in next month's final in Munich.
Chelsea drew first blood after a quick break saw Ramires find an unmarked Didier Drogba, who powered his shot past Victor Valdes in the Barcelona goal.
The visitors had good chances of their own in the first half and Lionel Messi came closest when he saw his dinked shot cleared off the line by Ashley Cole. Earlier in the half Alexis Sanchez had beaten Petr Cech but his effort cannoned back off the bar. The visitors pressed well in the second half but the Catalan giants couldn't find an equaliser, despite long spells of pressure.
After continuing their impressive home record, Chelsea have been cut from 8/1 (9.0) for the tournament outright and are now 6/1 (7.0) to win with William Hill.
But they still have a considerable task on their hands at the Camp Nou in six days' time, with Barcelona at 11/10 (2.10) to win.
Pep Guardiola will know his side will need to improve but their winning run of nine home consecutive games will be of some comfort. Nevertheless, Roberto Di Matteo will have done his claims for the permanent Chelsea role no harm with yet another impressive European display at Stamford Bridge.
The other half of the Spanish contingent in the competition, Real Madrid, suffered a 2-1 loss at Allianz Arena against Bayern Munich on Tuesday and are now 5/2 (2.50) for the title, while the Germans - who could play the final in their own back yard - are 7/2 (4.50).
What's clear is that the semi-finals did not go to plan for the two well-fancied sides in the tournament and if Bayern Munich and Chelsea can reproduce the kind of form then there could well be a winner from outside Spain next month.
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Jim Knight is Betting Editor at Goal.com and has been tipping football games since he was old enough to place a bet. He is a Leicester City fan, writer and member of the We Are Going Up Podcast
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