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The 'We Found Love' star shocks fans by travelling to her own show on the Jubilee line.
The singer, who was opening her 'Loud' UK leg of her global tour at London's O2 Arena, jumped on the tube and apparently even used an Oyster card.
RiRi posed for photographs with fans before she jumped off with her entourage at North Greenwich station.
The singer was then apparently spotted singing "escalator-lator-lator" to the tune of her hit 'Umbrella' as she went up the moving staircase.
She was then whisked away in a waiting car which drove her just 100 yards to the venue.
Fans immediately took to Twitter to post up pics and express their delight at meeting the 'We Found Love' star.
One fan wrote: "I cannot believe @Rihanna got the tube to the o2 tonight! But she did."
Another added: "I actually love that @rihanna went on the tube last night... Apparently it was to her own gig?! Either way, I love it :-)"
Earlier in the day the singer herself couldn't hide her excitement at kicking off her UK tour, tweeting: "I've been waitin 4 this all year."
The 'We Found Love' singer rounded off her night by beating Beyonce and Jason Derulo to the Best International prize at the 2011 MOBO Awards in Glasgow.
Giselle's journey with Rihanna
Gisells was lucky enough to bump in to the star on the underground.
Listen to Giselle talking to Capital about the moment she realised she was stood next to Rhanna...