I was 'surprised', as awarded a new World Cup winner's medal - Sonny Bill Williams

Williams handed his medal to 15-year-old Charlie Lines on the pitch as he celebrated the All Blacks' victory over Australia in Saturday's final at

 Twickenham.

In a late twist, Williams was called on stage at World Rugby's awards ceremony in central London on Sunday night to be handed a replacement.

"I'm really surprised, most of the boys would have done the same," Williams said.

Lines ran on to the pitch as the All Blacks completed a victory lap around the Twickenham pitch.

He was tackled by a steward as he drew close to the players but Williams helped him to his feet and along with head coach Steve Hansen began talking to the boy.

Williams then escorted Lines back to the stands before taking the medial from around his neck and placing it over his head.

The boy then kissed the medal and gave Williams a hug.

The 30-year-old was unaware he would be presented with a replacement medal but World Cup organisers acted following a request from the New Zealand players and management.

When on stage Williams also asked if team-mate Jerome Kaino would be given a new All Blacks beanie hat, with the flanker having given his to teenager Lines on Saturday night.