Beyonce Knowles made a surprise appearance at the Oscars, to join host Hugh Jackman for a spectacular medley of showtunes.

The pop superstar dazzled onstage at Hollywood's Kodak Theatre wearing a top hat and red sequined leotard and gloves.

Knowles and Jackman whizzed through renditions of Top Hat, White Tie And Tails; You're The One That I Want, from Grease; Lady Marmalade; All That Jazz; and Somewhere Over The Rainbow.

And they were joined onstage at the end by High School Musical stars Zac Efron and Vanessa Hudgens and Mamma Mia!'s Dominic Cooper and Amanda Seyfried for performances of Last Chance and Mamma Mia! from their respective films.

The medley was directed by Moulin Rouge filmmaker Baz Luhrmann.