The much-rumoured performance came about after the 'Real Slim Shady' star had been joined on stage at the Grammy Awards by Rihanna and Adam Levine from Maroon 5 for a rendition of his hit 'Love The Way You Lie', before Rihanna was replaced by Skylar Grey, who then broke into 'I Need A Doctor', which appears on Dre's forthcoming album 'Detox'.
As she began the song, the music mogul walked out onto the stage to join his pal and the singer to perform the track.
'Love The Way You Lie' had been nominated for four awards - Record of the Year, Song of the Year, Best Rap Song and Best Rap/Song Collaboration - but failed to win any of the accolades.
However, Eminem - whose real name is Marshall Mathers - walked away with two gongs for Best Rap Solo Performance and Best Rap Album for 'Recovery'.
Meanwhile, the big winners of the night were Lady GaGa - who was carried down the red carpet in a giant egg, before 'hatching' out of it ahead of a performance of her new song 'Born This Way' - who took home three prizes, and country act Lady Antebellum, who won five, including Song of the Year and Record of the Year for their hit 'Need You Now'.
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