The Voice UK's will.i.am had 'hardest ever' fight for show-stealing singer Donel Mangena

Sixteen-year-old Donel steals the show, while host Emma Willis tells will.i.am she has "never seen you pitch that hard for somebody."

However Donel risks being upstaged by his grandma Nita, who nearly steals the show back off him when she rushes out on stage following her grandson's performance.

"Donel’s amazing," said will at the launch of the ITV reality show. "I was pitching from deep down in my soul and I’m so happy that Donel’s on my team because we’re going to do a lot of great work together."

"That lit up my heart though," will added. "You could see the way he is with his grandma is the way that I was with my grandma. All the time I would go to the Grammys, my grandma would be my date and I see that in the love and just the appreciation for her wisdom and her joy and how she moves. It was a beautiful moment."

Addressing will at the launch, Willis said: "If [Donel] won and you did a duet with him, you’d have to get her involved!" To which fellow coach Jennifer Hudson added: "Imagine what her reaction would be if he won?"

Quite what Donel's grandma gets up to, you'll have to wait and see. But suffice it to say it's going to become a Twitter moment even faster than she raced up those shiny steps to the stage...

Meanwhile will.i.am also said that because he is "sleepy" at the beginning of the show, "there's a lot of parts" of the series that he doesn't remember until he watches it back on TV.

"So watching the show I’m like 'This is really, really entertaining. I don’t remember saying any of that stuff. I don’t even remember being there. All I know is that show is freaking awesome!'"

The Voice UK airs 8pm on Saturday 6th January on ITV