IT WAS billed as a comeback - but Michael Jackson's first UK stage appearance in nine years fell flat.

The fallen King Of Pop had been set to recreate his famous graveyard Thriller video at the World Music Awards.

But instead he joined a group of youngsters on stage to sing only a few lines of We Are The World.

During the fleeting performance, his voice appeared to crack and falter on the high notes.

Jackson's performance finished when the musical accompaniment disappeared - it was not known whether this was intentional or not.

His big hit, Thriller, was performed by another US star, Chris Brown.

Before Jackson sang on stage, there was huge excitement in Earls Court.

The Beat It star picked up a Diamond Award from US singer Beyonce.

He thanked "my fans all over the world".

"I dedicate this to the so many that have loved me and stayed by me throughout these years in the entertainment business," he said.

"While I cannot meet all of them I would like to thanks my wonderful children, Paris, Prince and Blanket for their unconditional love and support and my mother and my father, my brothers and sisters, my entire family for their love and support.

"I thank you I love you all, all the fans from the bottom of my heart."

He said that when he began making the Thriller album "it was my dream that Thriller would become the biggest-selling album ever".

Giggling and breaking off from his speech to tell fans: "I love you," after being overwhelmed by cheers, he told them: "God has answered my prayers 25 years later.

"Thriller has become the biggest-selling album of all time. I thank God and you for this success."

Presenting the award, Beyonce said: "If it wasn't for Michael Jackson I would have never have ever performed. He's made such a big impact on my life and on every performer's life.

"Michael Jackson, we love you. Congratulations to the King of Pop."

Jackson, who has rarely been seen in public since he was acquitted of child abuse charges in the US last year, touched his heart and blew kisses to the crowd as they stamped their feet in anticipation of what would in fact turn out to be a disappointing performance.

Before the performance began, he threw his jacket into the crowd as they chanted his name and he told them: "I love you. Thank you very much."

It was rumoured that the US star was driven the short distance from his dressing room to the stage.

The youngsters singing We Are The World included Tanya Morgan, 17.

Speaking before going on stage she said: "Today was the first day of rehearsals and we've not rehearsed with or seen Michael."

On his way to the event Jackson, who wore a diamond encrusted black jacket and his trademark drainpipe black trousers, had even said he was not performing at all.

The 18th World Music Awards - held in Britain for the first time - featured performances from Beyonce, Enya, Katie Melua and Nelly Furtado.

Former army officer James Blunt, 32, won two awards at the ceremony hosted by US party-animal Lindsay Lohan, for World's Best New Artist and Best-Selling British Artist.

Other attendees and presenters included Paris Hilton, Victoria Silvstedt, Jordan and Peter Andre, Rachel Hunter, The Sugababes, Jade Jagger, Lemar and Elle McPherson.

The show marked 10 years since Jackson's embarrassing appearance at the Brit Awards, when Pulp star Jarvis Cocker invaded the stage.

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