And clearly at ease doing the rounds on her own with out husband Prince William at her side, the 30-year-old had her companions in fits of giggles at the synchronised swimming event.
The group included Prince Albert of Monaco, who was clearly pleased to catch up with the young royal.
They chatted warmly after greeting each other with a friendly kiss on the cheek.
Kate was also on hand as history was made during the final of the first ever women's boxing final. She seemed delighted to see that the gold was claimed by great Britain's Nicola Adams.
The Duchess cheered the Leeds lass on to victory with help from Princess Anne and her husband Timothy Lawrence and Sir Steve Redgrave.
Earlier, Kate got the chance to check out some of the 52 medals – 25 of them gold – already won by team GB during Britain's most successful Olympics.
Accompanied by her brother-in-law Prince Harry, the royal dropped in on the Olympic village.
She was spotted congratulating the likes of gold winning rowers Sophie Hosking and Katherine Copeland and having a closer look at their medallions.