Ellie Goulding shocked a pair of superfans when she duetted with them on stage.

Ellie Goulding with superfans Martha and Lucy for MasterCard's Priceless Surprises campaign (c) David Parry

Ellie Goulding with superfans Martha and Lucy for MasterCard's Priceless Surprises campaign (c) David Parry

Best friends Martha and Lucy thought they were recording a version of Ellie's track 'Army' for a documentary but were left completely in shock when they were joined on stage by the 'Love Me Like You Do' hitmaker as part of MasterCard's Priceless Surprises campaign.

Ellie shared: "It was amazing to surprise Martha and Lucy. They are so talented and nailed some tricky harmonies. I was impressed.

"'Army' is about my best friend, so it was great to surprise two best friends. Their reaction was so worth it."

Whilst Martha gushed: "[It was] the best moment of our lives! I can't believe it really happened. There was a time when I thought I would never be able to sing again because of medical problems, and I've just sung on stage with Ellie!

"Ellie is amazing, and a huge influence for Lucy and I. When we first heard 'Army', we felt like it was written about us. It means so much that we got a chance to meet Ellie and perform it with her."

MasterCard have teamed up with a number of celebrities - including Ellie and Mark Ronson - to give their superfans something they won't ever forget as part of their Priceless Surprises campaign to celebrate the 2016 BRIT Awards 2016, which take place on February 24th.

Visit PricelessSurprises.co.uk to be the first to find out about upcoming MasterCard's Priceless Surprises with your favourite artists.