The pair from Manchester have been friends for ten years. Paula has been in a wheelchair for the last eight years.
They have previously won the UK Wheelchair Dance Sport Championship at debutante level.
After performing to the song 'Empire State of Mind (Part II) Broken Down' by Alicia Keys, David Walliams said: "I thought that was amazing, you turned what might have been a negative into a positive!"
Alesha Dixon was also full of praise, commenting: "Beautiful to watch, inspiring, refreshing, unique."
However, Simon Cowell's compliments were qualified, as he told Paula: "You are much better than Gary, by the way!"
Britain's Got Talent airs tonight at 8pm on ITV1.
> Britain's Got Talent: 14-year-old Paige's Bon Iver cover wows judges
> Britain's Got Talent show four: Show Bears, transvestites - pictures