Kate Middleton and Meghan Markle settled into the Royal Box in Wimbledon's Centre Court to watch Simona Halep be crowned Wimbledon Champion.
The houses of Sussex and Cambridge united to see the Romanian takedown Selena Williams in two quick sets.
With Pippa Middleton sitting on the left-hand side of Meghan and Kate on the right, the three women looked in high spirits as the final began.
Kate arrived early wearing a green short-sleeved Dolce and Gabbana dress with gold buttons.
She spoke to a group of junior players due to play in a girls' doubles semi-final on Saturday.
Meghan arrived shortly before the match began at 2 pm wearing a white top and a long skirt.
The Duchess of Sussex watched the first set sharing a collective sense of disbelief at how her close friend Serena was being dominated by Halep.
The American, who has been friends with Meghan since 2014, was broken twice in quick succession.
As Serena remained unable to find a foothold in the second set Meghan slipped on a pair of large sunglasses.
They weren't enough to hide the Duchess's nerves however, with the royal making several jittery asides to her sister-in-law.
It is the first time the pair have been seen together on their own in an official capacity since rumours of a huge fallout, including reports that Kate was in tears at Princess Charlotte's bridesmaid dress fitting.
Both royal women, who were together at a charity polo match earlier this week, have been to earlier rounds of the competition but on different days.
Kate, who has been a Wimbledon regular since 2011, stopped by on day two of this year's tournament to watch British number four Harriet Dart take on American Christina McHale.
Later she took a seat in Court 1's Royal Box to watch defending champion Angelique Kerber's opener and Wimbledon king Roger Federer in her role as patron of the All England Lawn Tennis Club.
Meghan's first trip to SW19 this year proved to be slightly more controversial.
The Duchess of Sussex was photographed sitting with two pals in the middle of a sea of green seats.
Tennis fans sitting near her were banned from taking photos of the royal, despite the match being shown live on the BBC.
One man was told off for taking a snap, when he was actually taking a selfie with the court in the background.
While an anonymous source told The Times that Meghan had committed a "massive faux pas" by not staying to watch Andy Murray's match after Serena's, others pointed out the Duchess had stopped by as part of a private engagement.
Meghan has been friends with the American tennis star for years and met her before marrying into the Royal Family.
Following her semi-final victory against Barbora Strycova, Serena was asked whether she hoped the duchess would ignore the criticism and continue to attend her matches.
She replied: "You know, I didn't know there was negative media out there.
"Any time I see her name attached to anything, I don't read it.
"She couldn't be a better friend to me. Low moments, high moments, she's always there.
"That's all I want to be to her."
A year ago Kate and Meghan watched Angelique Kerber beat Serena to the title in what was the royal women's first joint engagement as a pair.
Tomorrow Kate, who is patron of the All England Lawn Tennis and Croquet Club, is due to head back to Centre Court to watch the men's final with Prince William.
Prince Harry and Meghan have tickets booked to see the premiere of the Lion King in London.