Taylor Swift welcomed MTV Brand New For 2014 nominee Sam Smith on stage during her gig at London's O2 Arena last night (February 2).

The Everything Has Changed singer invited Smith to perform his debut solo single Money On My Mind with her - with the BRITs Critics' Choice winner gladly accepting her offer.

Thank you so much to the gorgeous @taylorswift13 for singing 'money on my mind' with me tonight at the O2!! pic.twitter.com/5znvyPADGN

— SAM SMITH (@samsmithworld) February 2, 2014

He later took to Twitter to exclaim: "I just got invited on stage to sing 'money on my mind' with @taylorswift13 at the O2!!!!!!!!!!!!!!!!!! Dying."

Sam then posted a pic of himself and T-Swizzle together backstage, writing: "Thank you so much to the gorgeous @taylorswift13 for singing 'money on my mind' with me tonight at the O2!!"

And, Taylor herself had nothing but praise for the talented 21-year old, tweeting: "Tonight at the O2, @samsmithworld sang my new favourite song "Money On My Mind" and smashed it! You need this song/artist in your life!"

His appearance comes after Swift's pal Ed Sheeran joined her on stage during Saturday's Red show (February 1), where they sung Lego House.

On the same night, a fan also gatecrashed her performance of We Are Never Ever Getting Back Together to hand Taylor a note, before being taken away by security!