Gymnast hoists David Walliams into the air by his MOUTH in daring BGT performance

Simon Cowell's jaw literally dropped as a gymnast managed to lift David Walliams off the ground with just his mouth on Britain's Got Talent .

Duo Julia and Alex from Coventry and Ukraine - known as DUO A&J - put on an acrobatics display that saw them using a rope to perform dangerous moves in the air.

One of those daring moves saw Alex positioned upside down with a rope in his mouth as Julia hung onto it, spinning freely high above the stage.

Curious to see if it was possible to do with his heavier weight, David Walliams was invited to hop on stage and try it himself.

David was thrilled when he was hoisted a couple of feet in the air (Tom Dymond/Thames/Syco/REX Shutterstock)

DUO A&J had performed the dangerous move in their routine (Dymond/Thames/Syco/REX)

Alex managed to lift Walliams several inches off the stage, much to the other judges' amusement.

As soon as David set sight on a topless Alex he jumped out of his seat to cheer them on, joking that they were already through to the next round before even performing.

When Julia explained that they were also a couple he pretended to act sad, and urged them to "just get on with it".

There were 'oohs', 'aahs' and gasps from the audience and the judges as Alex literally swept Julia off her feet.

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A curious David wanted to try it out (Tom Dymond/Thames/Syco/REX Shutterstock)

When Alex held Julia up by a rope in the challenging move, the judges were all gobsmacked.

Alesha remarked: "I almost didn't believe that was real!"

An impressed Simon added: "I love being surprised, that was amazing."

A&J were given four yeses, sending them through to the next stage of the competition.

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David Walliams took an immediate liking to topless Alex (Dymond/Thames/Syco/REX)

The pair wowed with their routine (Dymond/Thames/Syco/REX)

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Other successful acts included comical children's entertainer Graeme Mathews, from Essex.

There was also a troupe of female dancers and illusionists from the Netherlands, Angels Inc, who made dancers miraculously appear on stage during their powerful routine.

Walliams dubbed Angels Inc as "the Pussycat Dolls of magic" and that it was a performance "for the dads" as they received four yeses from the judges.

Britain's Got Talent continues on ITV next Saturday.