Chelsea-Lee James, 11, shed tears as she stood on the stage at Beyonce's Acer Arena concert in front of more than 20,000 people.

But they were tears of joy from this brave little girl plucked from the crowd by her idol.

After dedicating her final song, Halo, to Michael Jackson, Beyonce called Chelsea-Lee to the stage, the superstar embracing her big-hearted fan.

"It was breathtaking," Chelsea-Lee said.

"She said 'you're a great dancer,' and just sang to me, it was so cool," she said.

"Nothing else mattered in the world, it was me up there with Beyonce."

The emotion was not lost on the crowd, with the moment caught on video, uploaded to website YouTube and recording thousands of hits.

Beyonce knelt beside the awestruck girl, adapting her lyrics and singing "'Chelsea I can see your halo, I pray it won't fade away".

The words meant so much more because of Chelsea-Lee's extraordinary struggle, mother Donna James said yesterday.

The Herald documented the family's battle to have Chelsea-Lee's rare cancer, a primitive neuroectodermal tumour, diagnosed in 2003.

After three failed attempts in a year, Chelsea-Lee was admitted to John Hunter Hospital where doctors discovered a 20-centimetre tumour on her spine.

She was operated on within 24 hours and began five years of treatment, including chemotherapy and radiotherapy.

When four tumours returned in 2006, she was given a one per cent chance of survival.

Chelsea-Lee was again in remission, but the tumours could come back, Ms James said.

Far from focusing on the difficulties of her battle, Chelsea-Lee is excited about the newest addition to her speed dial.

"Beyonce phoned me up the next day and thanked me for coming on stage with her," Chelsea-Lee said.

"For Beyonce to do that without even knowing what Chelsea-Lee's been through, that shows she is pretty special," Ms James said.