Singer Michael Jackson has appeared on stage for the first time since being acquitted of child abuse charges.
But the pop star disappointed fans by singing just a few lines of We Are The World at the World Music Awards ceremony at London's Earls Court.
The star told reporters it had been a "misunderstanding" that he would sing his hit single Thriller.
The 48-year-old also scooped a tribute award for selling over 100 million albums throughout his career.
Beyonce Knowles presented him with the award, saying: "If it wasn't for Michael Jackson, I would never ever have performed."
Jackson received a standing ovation as he walked onto the stage.
He told the audience: "I love you. God has answered my prayers.
"Thriller has become the biggest-selling album of all time, with 140 million sold. I love all the fans from the bottom of my heart. I love England."
He then left the stage to boos from the crowd who had still expected him to sing.
He had also been booed by fans outside the venue for failing to meet them when he arrived, after they had queued for several hours.
The show continued with a performance from Rihanna, but just as Jackson fans were about to give up on seeing their icon perform, he reappeared on stage with a choir of 50 young people.
He sang two choruses of the song We Are The World before he threw his jacket into the crowd.
At the end of the song he spent time shaking hands with people in the front row before leaving the stage.
Michael Jackson was booed when he did not meet with fans
Initially it had been thought he would perform his big hit, Thriller, but instead that was sung by another US star, Chris Brown.
It was not the first disappointment of the evening for Jackson fans, as the star failed to stop and meet the hundreds of supporters who had waited for hours to see him on the red carpet.
Jackson's arrival in the UK has been the subject of intense media coverage, with fans and photographers camped outside his London hotel.
The singer has been based in the Middle East since he was acquitted on child abuse charges in 2005.
The World Music Awards which present prizes to artists based on international record sales, will be shown on Channel 4 on 23 November.
Were you present at the World Music Awards? Did you see Michael Jackson?
I was on stage with Michael Jackson as a part of the choir. It was an amazing experience but due to silly people running to Michael and jumping on him I don't blame him for not being able to sing a full song as he was being harassed.
Mohammed Al-Sabti, Kensington, London
To say Michael Jackson's performance was disappointing would be an understatement. Clearly most people, including myself, attended the awards solely to see a legend in action once more, and any rendition of his more popular songs would have satisfied that demand. It was however still a great honour to see my favourite musician in the flesh, an opportunity I never expected to receive in my lifetime, and a moment I will never forget.
Coincidentally, I went to see Jarvis Cocker on the other side of London - performing, having written some new songs and entertaining the crowd. Looks like his old adversary could teach Wacko Jacko a lesson or two.
My partner and I paid £100 each for our tickets and they were worth every penny. I had goose bumps just to be in the same room as Michael. We love you Michael!
Nick Sayers, Hurstpierpoint, Sussex
Even though it was a let down that MJ did not sing Thriller, I was one of the singers in the choir for the closing act and I had the best time ever. He was not a let down to the choir.
Paolo Mariani, London
The atmosphere at the awards was amazing. Almost everyone there came to see Michael and we weren't disappointed. People were cheering so loud it was deafening. Would have liked to see Michael perform the Thriller routine but hopefully there will be a new album and tour out soon. As for the boos, people booed at Rihanna because they wanted Michael. I felt very sorry for her. Michael was not booed at any time. Throughout the night loud chants for Michael could be heard, even during other artists' performances. It was clear he was the only artist the crowd wanted to see! I loved it.
I was so disgusted with last nights appearance from Michael. I used to love that man's persona and everything he stood for but in recent years he's not been doing himself any favours in the public eye. I, however, have always defended my childhood hero but last night was the final straw. He showed no gratitude and failed to deliver what we (his loyal fans) wanted. One last farewell on the big stage.
James Pouchly, Sale, Cheshire