Rumours of tension between the Sussexes and Cambridges was fuelled when a royal author claimed the palace deliberately tried to "avoid diary clashes" between Harry, Meghan, William and Kate, to prevent "competition". Wearing a breezy blue floral dress, round sunglasses, and a pretty side braid, Pippa appeared to be having a blast in her seat next to Meghan.
Meanwhile, Kate opted for a green emerald dress by Dolce & Gabbana, which she paired with nude pumps and a white purse.
While Meghan was there, a man was accused of invading her privacy when he stood in front of the duchess to take a selfie.
Kate is a longtime tennis fan and a tennis player.
"That's incredible. I didn't know that", said the Romanian, who clinched her first Wimbledon title.
The royals are expected to return to the tennis tournament together to watch the women's final.
Asked before Saturday's match which one person she would want watching in the royal box, she said: "Kate".
"She couldn't be a better friend to me".
Fans of the royals blasted Meghan on social media for reportedly banning anyone from taking her photograph at the event.
Prime Minister Theresa May also watched the action, joined by her husband Philip.
The seven-time Wimbledon victor has a total of 23 grand slams under her belt - just one away from Australian player Margaret Court's record of 24 which has stood since the 1970s. And that was before she was told that as the new champion, she'd get to meet them after.
She is patron of the All England Lawn Tennis Club (AELTC).
But Meghan's Wimbledon appearance attracted a flurry of negative press, with those sitting nearby reportedly warned by security not to take photos of her.
Wolf Hall actor Sir Mark Rylance, Doctor Who's Jodie Whittaker, War & Peace star Lily James and Poldark's Aidan Turner also received an invite to the Royal Box.