The Princess of Wales finished second best after taking on double Olympic champion Dame Kelly Holmes – at a game of bean-bag noughts and crosses.
Kate Middleton, who is known for her competitive streak, joined a team of pupils being supported by Dame Kelly’s trust at its base in Bath, with the former sports star on the other team.
The children from St Katherine’s School in Bristol are taking part in the On Track To Achieve programme, delivered by their athlete mentor and Paralympic gold medallist Liz Johnson.
In bright summer sunshine on Tuesday, the opposing groups had to run forwards in turn and throw a bean-bag on to a grid on the ground.
Kate did her best but Dame Kelly’s team won twice.
After the first victory, the track and field star held her arms aloft and admitted she is “slightly competitive”.
The princess joked: “You would never have guessed.”
Dame Kelly founded her national youth development organisation on the belief every young person needs a champion.
It pairs world class athletes with youngsters, who may lack confidence or have other issues, so the sportsmen or women can pass on their winning mindset and help the schoolchildren develop the skills and confidence they need to succeed in life.
The princess later sat down to chat to the pupils, all girls aged from 11-13, who spoke about their experiences at school, home life and the benefits of being mentored by a sports star.
Kate, who this year launched her early years development project called Shaping Up, visited the charity on Tuesday (16 May) in her first in-person royal engagement since the coronation of King Charles III and Queen Camilla earlier this month.
However, she made a surprise appearance in a pre-recorded video during the 2023 Eurovision Song Contest on Saturday (6 May).
Fans were delighted when they saw Kate playing the piano for a short clip in Ukraine’s Kalush Orchestra’s opening performance.
Kalush Orchestra were last year’s winners and performed their winning song “Stefania” at the start of this year’s competition.