The Black Eyed Peas star is seen performing the song to the audience during a break in filming.
Will gets the crowd on their feet with his performance, as more acts prepare to take to the stage during the blind auditions.
It's week 5 of the singing contest this Saturday night, as the four coaches continue to build up their teams.
Will.i.am, Olly Murs Sir Tom Jones and Jennifer Hudson are this year's coaches who are on a quest to uncover the best vocal talent that Britain has to offer.
Once again, this year’s winner will win a life changing record contract with Polydor Records.
As always, the first stage is the blind auditions where the contestants must hold their nerve as they sing to the backs of the coaches.
If any of them like what they hear, they bash their buzzer to spin around and select that artist for their teams of ten.
After the first four weeks, Olly currently leads the way with seven of his ten acts chosen. Both Will and Sir Tom have six while Jennifer has only half her spaces filled as things stand.
Another set of singing hopefuls will perform to the backs of the coaches on Saturday evening.
They include 16-year-old student Saskia Eng from Edinburgh who sings London Grammar's Strong.
Backstage hosting will be Emma Willis.
She said: “I love this time of year because, if I’m lucky enough to get invited back, it means I get to eavesdrop in on some of the most sensational singing talent that this country has to offer whilst hanging out with the megastar coaches.
“It’s an absolute treat to get to work on The Voice UK, I love every minute of it, and I can’t wait to get started."
The Voice UK 2018 airs Saturday night on ITV.