RiRi unexpectedly joins Jay-Z for `Run This Town` duet

London: Rihanna, who is not due to headline until Sunday, couldn’t resist getting an early start and joined her mentor Jay-Z for an unexpected ‘Run This Town’ duet on Radio 1’s Hackney weekend.

The 42-year-old rapper opened his set with a blistering performance of the song then was joined by his protégé, the Daily Mail reported.

In short black shorts, a bra top, trainers and a black top, the 24-year-old singer was effortlessly cool as she confidently shared the stage with the hip hop artist.

Despite the poor weather and darkness around, the ‘Umbrella’ singer showed off her superstar credentials in a pair of goggle like shades.

The rap star wore camouflage jacket with dark trousers as he powered through his set watched by proud wife Beyonce Knowles.

M.I.A. then joined Jay-Z for ‘Paper Planes’ but after her microphone failed the pair performed another song ‘Bad Girls’ to the delight of the crowd.

Jay-Z also performed his past hits like ‘99 Problems’, ‘Bonnie and Clyde’ and ‘Girls, Girls, Girls’.