Katy Perry, JLS and Taylor Swift joined inspirational young people on stage at a ceremony celebrating the achievements of British teenagers.
The stars presented awards to three 16 and 17-year-olds as part of BBC Radio 1's Teen Awards, held in front of an audience of thousands at the Hammersmith Apollo in London.
Katy gave the award for Teen Hero to Connor Rowntree, 16, from Sunderland, who has had nearly 100 operations after an accident that left him with severe burns.
Connor nearly died on six occasions but now fronts a campaign for fire safety, inspiring other teenagers across the country with his determination.
The Teen Community Hero award went to Alex Williams, 17, from Ashton-under-Lyne, who lost the use of his legs when he got meningitis at the age of seven.
As well as helping other disabled children, he is now a sports ambassador for his local area and a wheelchair basketball player with ambitions to take part in the Olympics.
Jack Bennett, a 16-year-old from Maidenhead, was named Teen Entrepreneur after setting up a free-range chicken farm for his local community.
Fearne Cotton, who hosted the event with fellow Radio 1 DJ Nick Grimshaw, said: "All of the teens nominated in the Teen Awards have been outstanding, but Connor, Jack and Alex really impressed our judges with their incredible stories.
"It's been a smashing day and, judging from the noise at the Hammersmith Apollo, the audience have had a great time too!"
With performances from The Wanted, Professor Green and former X Factor contestant Olly Murs, the evening also involved a number of celebrity winners, as voted for by Radio 1 listeners.