Carrie Underwood joined Mick Jagger and the Rolling Stones on stage to sing their hit 'It's Only Rock 'n Roll (But I Like It)' over the weekend. The surprise was spoiled by a tweet at the rock band's Twitter page, but the performance was as alive and enthusiastic as one would expect from two legends of their respective genres.

Underwood took the stage alongside Jagger in Toronto, Ont. on Saturday, just two days after wrapping her Blown Away Tour with Hunter Hayes in British Columbia. She was clearly starstruck, smiling from ear to ear during the entire four-minute performance. She couldn't take her eyes off the enigmatic lead singer, and afterward she confessed to being overwhelmed, but in a good way.

"I just sang with the @RollingStones!" she tweeted. "Holy cow! I walked off stage and said, 'What just happened?!' Still can't believe it!"

Earlier in the day, the Stones let fans know that country music's first 'American Idol' would be joining them. "Just done a great soundcheck with @carrieunderwood ~ looking forward to the gig tonight," guitarist Ronnie Wood tweeted.

The performance came exactly eight years after Underwood won 'American Idol.' She wore a Rolling Stones T-shirt over tight black pants and did her best to keep up with Jagger's dance moves. Video of the performance can be seen below.

Watch Carrie Underwood and the Rolling Stones Sing 'It's Only Rock 'n Roll'