A budding young pop singer says she got the surprise of her life from one of the world's biggest pop stars while performing at one of the world's largest shopping malls this weekend.

Sydney Bourbeau was half way through covering Ed Sheeran's Thinking Out Loud at West Edmonton Mall on Sunday when Sheeran himself, who just happened to be at a nearby music store, hopped on stage and helped her.

The 13-year-old Grade 8 student says she initially thought Sheeran, who was wearing thick-rimmed glasses and a plaid shirt, was a stage hand coming to help her with the microphone stand.

With the crowd roaring its approval and people scrambling for their phones, Sheeran and Bourbeau shared the mic for a verse and a chorus.

Then, giving Bourbeau a hug, the British megastar was gone as quickly as he arrived, allowing the youngster to finish up.

Bourbeau was performing at the mall as part of a concert to mark the end of a fundraiser for the Humane Society hosted by her music school Resonate.

The music school later confirmed that they didn't know Sheeran was at the mall, and they didn't plan the performance around his concert.

Later Bourbeau got another surprise when Sheeran's manager texted her, offering her two tickets to the award-winning singer's concert at Rexall Place.

With files from CBC News and Jennifer Van Evra