Louis Tomlinson has said singing on The X Factor days after the death of his mother 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.
Johannah Deakin died on Wednesday at the age of 43 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.