Doncaster's Louis Tomlinson: Performing on X Factor days after mother's death was 'harder than I ever imagined'
The One Direction star said she would have been "proud" to see him perform his new single, Just Hold On, on Saturday night's show.
Mum-of-seven Johannah Deakin died on Wednesday at the age of 42 after a battle with leukaemia.
Tomlinson, 24, thanked his fans and Steve Aoki, the US DJ he collaborated with for his latest record, for their support on Twitter.
He said: "That was harder than I ever imagined. I want to thank everyone around me and all of the amazing fans out there that made that so special!
"Feeling so much love around me and my family . Mum would have been so f****** proud ( sorry for swearing mum) love you !
"Also @steveaoki , you have been such a rock and inspiration throughout this ! Pure talent and a real gent !"
After receiving a standing ovation from the judges, Tomlinson fought back tears as Simon Cowell, who manages One Direction, commended his performance.
He said: "I've known you now for six years. What you've just done, the bravery you've shown, I respect you as an artist, I respect you as a person.
"Your mum was so proud of you, she was so looking forward to tonight and she's looking down on you now. Steve, you're a great friend to him."
Tomlinson blew a kiss up to the ceiling as he listened to Cowell's tribute.