Rita had been booked to perform at the Belvedere Vodka DKNY Art Works party in London, but revellers had no idea that they'd be getting two for the price of one!
Cara, who was hosting the party, jumped on stage alongside her BFF and grabbed hold of the mic. The model also tried her hand at rapping along to Notorious BIG's 'Juicy'!
The pals appeared to be having a whale of a time, especially while busting some dance moves together.
As Rita sang her heart out, Cara crouched down behind her and threw her hands up into the air. Her facial expression also told us that she was trying really hard!
Engaged couple Professor Green and Millie Mackintosh were also at the event, which was held at Lambeth Fire Station, and saw Cara and Rita's performance.
But Pro Green, who was on crutches following a recent accident, tweeted: "So @RitaOra is dancing with Cara, the bird's enjoying it but I'm not allowed to look. #doublestandards." Oh dear!
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