Oli Ross, 21, impressed with her rendition of Awolnation track Sail on Saturday's episode of the talent show.
-> Watch as incredibly talented Leeds busker shocks crowds with her opera voiceThe ITV programme delved into Oli's close relationship with her mum, Annette, who talks of her daughter's support in her fight with multiple sclerosis.
During the show's blind auditions section, hosts listen to contestants with their backs turned, and if they want to represent the singer during the battle stage, they swivel round to face them.
Sir Tom Jones was the only one of four judges not to pick Oli.
Speaking before going on stage, the contestant said her first memory of singing was while watching the film Dreamgirls.
She said: "I just belted this really, really big note. My mum literally started crying.
"My mum is my favourite person. We argue like cats and dogs but we are the same person, it's ridiculous."
She added: "My mum's got MS, multiple sclerosis, she's not had it great to be honest.
"Life has dealt her some absolutely ugly cards and she's the best person that I know."
-> Work starts on vital flood protection work for LeedsIn an interview, her mum said: "She's always there for me and as the illness progresses, she's always the first one, every day, to ring me and ask how I am, and I always reply: 'Still gorgeous, darling'."
The NHS describes MS as a life-long condition that can affect the brain and spinal cord, causing a wide range of potential symptoms, including problems with vision, arm or leg movement, sensation or balance.
Speaking before her performance, Oli said: "I'm nervous but the nerves are channeled with adrenaline and fire and I'm excited.
"If I won this, the fact that people could be listening to me for my music and loving what I'm doing is insane to me.
"I think it's a bit too much to put into words how much this would mean to me."
-> Channel 4 decides not to relocate team to new Leeds headquartersAmerican singer Trainor instantly took to Oli's performance, and was the first to swing around in her chair.
She told Oli: "You're so cool. That's a very hard song to sing and you came out here and delivered. I was like, oh my God I'm going to win and then you [turning to will.i.am] ruined it."
The rapper said her performance was "perfect".
Murs added: "It was just incredible, it really, really was and that's why you've got three turns.
"You genuinely are a fantastic singer and that's what the Voice is about."
Oli chose Trainor to represent her in the show after the star said she would have an "awesome career".
The next stage of the competition, when contestants battle against each other, is due to start mid-February.
Saturday's episode can be viewed on ITV's online player.