Simon Cowell got emotional as a father and sons vocal group and a teenage singer became the latest acts added to the grand final line-up of Britain’s Got Talent.

It was 15-year-old Isaac Waddington who won this semi-final after Cowell told him he had put on a fantastic, fantastic performance.

Alesha Dixon said she found his voice hypnotic, and told him I want your album.

But it was The Neales − a four-piece vocal group consisting of singing solicitor Laurie Neale and his three sons, James, Dan and Phil − who brought out Cowell’s sensitive side.

I actually got quite emotional. What’s happened to me?

They sang Father and Son and, when they finished, Cowell said “God, I actually got quite emotional. What’s happened to me?”

He added: “I really like you guys.”

David Walliams described their performance as incredibly emotional, and Amanda Holden said: “To make Simon cry is huge.”

After Waddington was named as the winner, the judges had to choose between The Neales and dance troupe Boyband.

Despite his emotions running high earlier, Cowell chose to put Boyband through to the final, but the other three judges all chose The Neales, meaning that they will join Waddington in the final.

Every night this week contestants have been performing for a place in Sunday’s final, with the hope of winning a £250,000 cash prize and the opportunity to appear at the Royal Variety Performance.

Welsh choir group Cor Glanaethwy and dance group Entity Allstars became the first acts to go through to the final on Monday night.

Performing dog act Jules O’Dwyer and Matisse won Tuesday night’s semi-final, while dad-dancing five-piece Old Men Grooving also became finalists.

Magician Jamie Raven and Siberian dance troupe UDI were also put through. (PA)