Blue Ivy Joins Beyonce at London Concert

Beyonce introduced her "best friend" Blue Ivy Carter to concertgoers at her Mrs. Carter World Tour stop in London over the weekend.

A fan posted a video of the rare moment on YouTube and it's a beautiful sight to see.

Queen Bey was performing her No. 1 hit 'Irreplaceable' at the O2 arena and near the end of the song, the R&B mom made hand to hand contact with Blue Ivy. Don't worry, the tyke was wearing green headphones to protect her ears from the loud music.

While the video is a little unclear, it looks like Blue Ivy was wearing a dress -- but her curly hair is unmistakeable. She also looked around in amazement at the crowd singing along to Beyonce's hit song. Yes, Blue Ivy, people love your mama.

Fast forward to the 5:42-mark if you don't feel like watching the entire spectacle.

While we wait for some new music from Beyonce, she can be heard on 'The Great Gatsby' soundtrack, which is executive produced by her hubby, Jay-Z. She has a duet with Andre 3000 called 'Back to Black,' which is a cover of the Amy Winehouse song of the same name.

Watch Beyonce's 'Irreplaceable' Video