Dwayne Johnson, "You Rock!"

That's what 100-year-old Marie Grover from Philadelphia said after being serenaded for her centennial birthday by none other than The Rock in a sweet video message.

In the personalized video, posted to Twitter Tuesday, Johnson smoothly belts out "Happy Birthday" to Grover, "who turns 100 years old today and I'm so honored that she's my fan," the actor sang. He blew kisses in honor of his fan's "beautiful age."

"I'm sending so much love and a HUGE congratulations on 100 years," Johnson said. "What an amazing life. … I'm very happy you were born and I'm so honored.

The actor, 47, added: "You can eat cake, you can get drunk. Party hard."

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Grover, who is affectionately called "Grandmom Grover," smiled from ear to ear in between laughs while sitting in her recliner flaunting a "100 & Fabulous" sash.

"Love you right back, you Rock, you!" an overjoyed Grover responded to the video.

Johnson said the sweet encounter reminded him of his own grandmother. "Wish my grandma was still around, but stuff like this is always the best part of fame," he tweeted.

The video was made possible by Jamie Klingler, the best friend to Grover's granddaughter, who sent a Hail Mary to Johnson on Twitter in late September.

"Oh my god-my punt to get @TheRock to wish my best friend’s gram a happy 100th birthday as she adores him might work," she tweeted on Sept. 22. "She will lose her mind. When we were in high school (25 years ago) she would wear a rock sweat shirt and tell us how handsome he is."

"I cannot begin to thank @TheRock enough for making this happen," Klingler tweeted Tuesday along with Grover's priceless reaction to Johnson's heartwarming shout-out.

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