A video that has gone viral on social media shows a woman getting a heartfelt handshake during a birthday surprise.

Some friends of a lady arranged a special birthday surprise for her, in which the lights would be switched on and everyone would wish her a happy birthday when she arrived, unaware that people were waiting for her.

However, instead of waiting for the celebrant to enter before saying something, one of her friends entered the room first and attempted to sing the birthday song.

Two seconds into the song, one of the other women in the room who held a camera phone and was recording, quickly shut her up with a factory-resetting slap.

Shortly after the slap, the celebrant entered the room to the warm embrace of friends and happy birthday wishes.

The lady who was slapped could be heard tackling the one who slapped her.

Watch Video below: