Dwayne Johnson croons a Happy Birthday to 100-year-old fan

While a telegram from the Queen is totally fine, it's not quite a singing telegram from The Rock, now is it.

But that's what 100-year-old Marie Grover from Philadelphia got.

A 30-year fan of the wrestler turned actor, it was a friend of Marie's granddaughter who sorted out the treat for this milestone birthday.

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After spotting a tweet about the plans to get him to mark the occasion, Johnson, who appeared initially oblivious, got straight onto it.

The Fast & Furious star recorded himself crooning Happy Birthday to the centenarian, explaining how 'honoured' he is to have her as a fan.

Grandmom Grover was filmed as she received her message, shouting back: “LOVE YOU RIGHT BACK, YOU ROCK YOU!”

Johnson, less than half her age at 47, then added: “You can eat cake, you can get drunk. Party hard.”

We're quite positive that she did.

He re-tweeted the video too, to his several billion Twitter followers, explaining how stuff like that is ‘always the best part of fame’ (presumably aside from the fast cars and swimming pools filled with cash).

Doubtless Grandmom Grover will be heading to the multiplex for his next project, the Jumanji sequel, Jumanji: The Next Level, in which he’ll be reprising his role as the rippled adventurer Dr. Smolder Bravestone.

Then it’s the Disney theme park ride movie Jungle Cruise with Emily Blunt, due for next summer.