The Princess Royal was grinning from ear to ear as she attended Epsom Derby Day with her family, while the Queen watched from home.
The monarch did not attend the major sporting event on Saturday, opting to view it on television from Windsor Castle, where she has been sent a souvenir race card to follow the action.
Anne, alongside her husband Vice Admiral Sir Tim Laurence, arrived at the sold-out racecourse in Surrey just before 1pm as part of a procession, which included her children Peter Phillips and Zara Tindall, who was with her husband, former rugby player Mike.
Peter, 44, was pictured with his girlfriend who has been named in numerous reports as Lindsay Wallace, despite it being rare for the girlfriend of a member of the royal family to attend a high-profile event.
Crowds cheered and waved union flags as they made their way in to the course, with Anne seen smiling.
She appeared in the royal box while the national anthem was played by a band.
Afterwards Anne could be seen waving and laughing, while thanking those around her for a warm welcome.
The princess was later given a painting of Dunfermline, the Queen’s winner of The Oaks race in 1977, as a gift to the monarch.
Peter, Zara and Mike could be seen on the balcony of the royal box during the second race of the day, though no celebrations took place after filly Bashkirova claimed victory.
Jubilee celebrations took place in the Queen’s absence, with 40 jockeys who have ridden for the owner-breeder donning the royal racing silks and forming a guard of honour before the national anthem was sung.
Five of the monarch’s former racehorses were also paraded, and a selection of hats inspired by the seven decades of her reign have been displayed.
Frankie Dettori and Willie Carson, who has ridden some of the Queen’s most memorable winners, lined part of the course with the other jockeys.
Describing for BBC News the pride he has felt while riding for the Queen in her racing colours, Dettori said: “Every time you see these (colours) on your peg you (have) this sense of importance and it’s a great honour.
“Look she’s a big lover of horse racing, and like you say she’s only missed the Derby twice.
“But I’m sure today she’ll find a TV and she’s going to watch it live because she loves the Derby so much.
“She’s been breeding horses for over 60 years she knows all the blood lines and she’s won lots of races and she’s very knowledgeable.”
Carson said: “She (the Queen) is the patron of racing and she has been a great advantage to horse racing.
“Her racing is her passion and everybody who takes an interest in the royal family will understand that her hobby is her horses.”
Among the famous faces in attendance were Downton Abbey star Jim Carter and fellow actress wife Imelda Staunton, comedian Lee Mack and tennis coach Judy Murray.
Staunton, who plays the monarch in The Crown’s upcoming series, said: “I’m very honoured to be in a place that the Queen obviously loves greatly – her big passion is horses.
“I know there’s a big pop concert tonight, but I don’t think that was her passion. This is her passion, so it’s very nice to be here, somewhere that she really loves.”
It comes after the Queen’s only runner Just Fine was removed from the World Pool Northern Dancer Handicap at the 48-hour declaration stage on Thursday.
Her hopes of winning the Derby were dashed earlier in May when her horse Reach For The Moon, who was among the favourites, and two others were withdrawn.
Thoroughbreds owned by the Queen have won four out of the five flat racing classics, the 1,000 Guineas and 2,000 Guineas, the Oaks and the St Leger, with only the Derby eluding her.
