X Factor 2010: Bookies favourites Matt Cardle struggles through 'worst song' while Rebecca Ferguson wows judges

By EMILY SHERIDAN 'Not my best performance': Matt Cardle admitted he struggled during his second song on tonight's X FactorHe's been favourite to win this year's X Factor, since the live shows began in October.But tonight Matt Cardle's potential to clinch the title wasn't looking so certain after he gave a 'safe' performance of Billy Joel's Always A Woman.After missing most of the week after