The joint bottom-weight was the last horse to get into the big-race field when the declarations were announced on Thursday.
Like Lochsong, the 9/2 favourite is owned by Jeff Smith and is from the same family, with her grand-dam, Lochangel, being a half-sister to the 1992 winner. She was always travelling kindly for her jockey, David Probert, and accelerated away from the field in the final furlong in the style of a very good horse, recording a one and a quarter length victory from runner-up Orion's Bow.
As owner and breeder Smith explained after the race, Dancing Star's victory was very much a family affair for his Littleton Stud operation.
"This is a grand-daughter of Lochangel, who is a half-sister to Lochsong," said Smith. "Lochsong won this when she was four and I think she was the last filly to win the Stewards' Cup, so we are keeping up a good family tradition.
Trainer Andrew Balding was delighted for Smith and was also very impressed with the winner's performance.
"She has won it so well," said the trainer. "We had a good draw but you have got to be impressed and she is a very special animal. I am feeling very blessed and very lucky not only to have a filly as good as her but also to get into the race. I think it was a little more luck than judgement there - we just crept in - and to get the draw, everything fell into place.
"Dave gave her a lovely ride and I am so thrilled for Jeff. He is such a good supporter and a great man to train for. I am delighted for the whole yard - the whole team deserve it.
"We have had a lot of the family. Her dam was quite good but had an awful habit of hanging and throwing her race away. She is a pretty good broodmare, so we are not disappointed now.
"I think we will probably put her in the big sprint at the end of the year. I don't want to pick up an unnecessary penalty - it would be nice if she stays in training next year and, if she is going to win something, it might as well be something big, so it will probably be the six-furlong race on Champions Day (at Ascot).
"She has improved a huge amount from two to three and has improved all year. The whole family have done it and she is a year ahead of Lochsong already.
"I can't remember how long David has been with us, but he is older than he looks. He is a solid and very good jockey. He might not be the height of fashion but he doesn't let me down very often, so I am delighted for him."