The 'Price Tag' singer faced the tough job of whittling down her seven remaining artists to just three in tonight's second round of Knockouts.
First, she had to give out her 'Fast Pass', which would send one of the hopefuls through to the live shows immediately.
"It's never a free pass, this doesn't mean the hard work stops," she commented. "The person that I'm taking through for me is just someone that has a voice that is undeniable."
Jessie then confirmed it would be going to Ash, who responded: "Thank you so much. You've been an incredible coach. From day one you've given us so much time and nurturing."
The remaining six were then divided in to groups of three, who would each sing a 'killer song' of their choice in an attempt to bag one of the other two spots.
The first knockout involved Sarah, Danny County, and Trevor Francis, but the closely fought contest left Jessie struggling to choose between them.
After seeking advice from her fellow coaches, she eventually concluded: "Danny, I'm being real with you, I believe you are the most unique artist this show has ever seen, but I'm not gonna put you through because I don't think that was the best voice.
"I'm gonna go with the person that showed me something that I haven't seen that deserves to fight in the lives, so the winner of this knockout is Sarah."
Later, Letitia Grant-Brown and Lovelle Hill locked horns with Matt Henry, who Jessie stole from Team Will.i.am during the Battles.
After their sing-off, Jessie said: "Letitia, you know how I feel about your voice, I think you're one of the best undiscovered young female vocalists this country's ever seen.
"Lovelle, the light and the shade you showed in your performance and the trust that you had in me was probably the most beautiful thing to see unfold.
"Matt, you were my steal, and I can't deny that every single person in this room was amazed. The winner of this knockout is Matt."
The Voice UK continues this Friday at 7.00pm on BBC One, when the top twelve artists will sing live to the nation for the first time.
Browse pictures from tonight's Knockouts episode below: