Valentina Attard, a 15-year-old Maltese-Australian, excitedly told Facebook friends on Friday that music superstar Beyoncé Knowles had made eye contact with her at a concert in Melbourne.

But nothing prepared the teenager for her once-in-a-lifetime experience when, the following day, she returned to watch the concert a second time and Beyoncé photobombed a picture that Ms Attard took of herself.

The photo has since gone viral, even on Beyoncé’s official Facebook page – which has more than 52 million likes – posted with the caption “Photobomb!”

Photobombing is a term used when a person drops in on a photo unexpectedly, sabotaging the picture.

And wowoowow it was the best moment ever

The Melbourne teenager said it was the first time she had seen the R&B singer live and she went away with a picture she will treasure forever.

When Ms Attard asked the global singer for a photograph during the concert, the 15-year-old turned her back to snap the picture and Beyoncé leaned forward to fit the frame of the selfie.

A selfie is a self-portrait that is usually taken with a hand-held camera or phone.

“I asked Beyoncé for the photo and then she posed, which was so nice of her,” said Ms Attard, whose father is Maltese.

But the young woman did not immediately realise she had taken the “perfect selfie” with the singer. A couple of days after the concert, she posted the picture on social networking site Tumblr.

She wrote on her blog that the experience was all but a “blur”.

“I just remember her bending down close to me and my friend and I just turned for the photo and wowoowow [sic] it was the best moment ever. Like she posed. It’s crazy, I wasn’t even expecting her to look at my phone or notice me in the crowd.”

The photo has gone viral on news media, including yahoo.com and the Herald Sun.

Popular British news site dailymail.co.uk has dubbed it the “best photobomb ever” and E! also headlining the article on its front page with “Best Photobomb Ever. Let this be the selfie that ends all selfies.”