Music
The pair sung 'I Know Him So Well' together, although Boyle is believed to have been unaware of the duet until shortly before the performance, the Daily Mail reports.
Boyle said: "I never thought I would see myself standing on the same stage with such an icon from West End theatre, let alone singing with her as an equal."
The Britain's Got Talent runner-up told the panel that Paige was her inspiration during her first audition on the reality talent contest.
Paige herself later expressed her support for Boyle and suggested a duet soon after that first performance.
Piers Morgan will present Boyle with a gold disc for her debut album I Dreamed A Dream during the special, which will air after the X Factor final this Sunday on ITV1 and on TV Guide in the US.
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