Chelsea v Barcelona (Kick-off 7.45pm). Coverage of the semi-final first-leg encounter at Stamford Bridge. Having battled past Napoli and Benfica in the two previous rounds, the Blues now face their greatest challenge of the knockout stage. Reigning champions Barcelona will go into this match as favourites due to their outstanding form in this season's competition, which saw them win five of their group matches, with the other being a draw, before beating Bayer Leverkusen and AC Milan in the knockout stages. The encounter also gives Chelsea an opportunity to gain a form of revenge after being eliminated by the La Liga side in the semi-finals of the 2008/09 competition, when Andres Iniesta's second-leg injury time winner put Barca through to the final on the away goal rule. Presented by Bill O'Herlihy, with commentary by George Hamilton and analysis from the Witches of Eastwick.