The Duchess of Cambridge was captain of her school hockey team but Kate turned expert cheerleader for the British women's team as they claimed an Olympic bronze medal.
Kate sat with gold medal winners Dame Kelly Holmes and Katherine Grainger as she cheered the Team GB women to victory against New Zealand.
After the match Kate, who was wearing a white Team GB T-shirt, hugged team captain Kate Walsh and praised the players. The Duchess, who captained her first XI at Marlborough College, also visited the team during pre-Games training at the park.
Walsh, who fractured her jaw when she was hit by a stick during a game last week, said: "She said congratulations and we all looked like we'd worked so hard, she gave me a little hug and just said I was really brave."
The hockey bronze came as Britain scored more Olympic success with its sailors and boxers all adding to its medal tally. There were silvers for sailors Hannah Mills and Saskia Clark, and Luke Patience and Stuart Bithell.
The day's action means Team GB's medal haul at London 2012 is now 57 - 25 gold, 15 silver and 17 bronze. But there was disappointment for gold medal hopeful Shanaze Reade, who could only finish sixth in the women's BMX at the Velopark.
Prime Minister David Cameron, his wife Samantha, Chancellor George Osborne and David Beckham were among the 6,000 crowd willing Reade to victory, but the 23-year-old Crewe rider started poorly in the final and could not recover. She said: "I'm pretty emotionless. I'm sure it will sink in, but the Olympic Games is the biggest platform you can race at and you've just got to give it your best. I just tried to stay focused and do my absolute best and today it just wasn't good enough."
Two boxers won their way through to finals tomorrow, securing the chance to go for gold and meaning Britain is guaranteed at least two more silvers. Luke Campbell, 24, from Hull, will take on his family friend John Joe Nevin, of Ireland, as he bids to fulfil his lifelong ambition of winning an Olympic title. Welshman Fred Evans, who has delighted crowds with his no-holds-barred approach, will also hope to continue his magnificent run in the welterweight division.
On the track, Britain's sprint relay woes continued as another baton changeover mistake cost them a place in the 4x100m final at the Olympic Stadium.
In taekwondo, Britain's Lutalo Muhammad, 21, earned himself a bronze medal after beating Arman Yeremyan of Armenia in the under-80kg category at the ExCeL. Boxer Anthony Joshua also beat Kazakhstan's Ivan Dychko in his semi-final bout to secure his place in Sunday's final and at least another silver for Team GB.