The Mamma Mia! beauty turned 27 on Monday (03Dec12), and to mark the occasion Jackman - who plays the star's father in the upcoming movie musical - turned the spotlight on Seyfried.
The actor grabbed a microphone and told the crowd, "Tonight is a special night, and I am going to sing one song. And this is a song I am not going to sing alone, because it is the birthday of Amanda Seyfried."
Jackman then ordered his pal to sit down as he gyrated around her and joked, "I once gave Barbara Walters a lap dance and I promised her I would never do it again, but seeing as she is not here tonight..."
The X-Men star sang to Seyfried, and referenced their Les Miserables relationship, declaring, "Happy Birthday, Amanda - my daughter Cosette - Seyfried. Yes, it’s one of those father daughter relationships... Happy birthday to yooouuuu!"
According to Vulture.com, Seyfried was presented with a chocolate birthday cake, and she said, "I was just thinking that my 27th year is probably going to be best because it was brought in in such a way that my hero, Mr Hugh, got to stretch his (vocal) cords one more time for me."