Gwyneth Paltrow - Paltrow's Surprise Performance On Glee Tour

The Glee stars are currently taking their live stage show across Britain and on Wednesday they performed at London's O2 Arena.

Fans were given an extra special treat during the performance when Paltrow, who has cameoed on the hit series as substitute school teacher Holly Holliday, made a surprise appearance.

Naya Rivera, who plays Santana Lopez, announced to the audience that she had been named the sexiest Glee club member during the tour, when Paltrow strutted on stage and challenged her to a sing-off.

The Hollywood star then launched into a rendition of Cee-Lo Green's hit track Forget You, which she performed on the show, before the rest of the cast joined in.

And Paltrow used the appearance to treat some young fans by taking them along to the show.

She wrote on Twitter.com following her slot, "Just took four 7 year olds to glee live london. Somebody pass me something vaguely hallucinogenic."