Zara Phillips has won a silver medal in her debut Olympics after the British eventing team held onto second place in a tense final phase.
Phillips and a British team including Tina Cook, Nicola Wilson, William Fox-Pitt and Mary King came second to favourites Germany after the show-jumping.
The royal had set nerves rattling by knocking down a pole and racking up three time penalties with her round but King and Cook both jumped clear to secure the silver, leaving New Zealand with bronze.
It is Britain's 18th Olympic post-war eventing medal and means Phillips has gone one better than her mother, who competed in the Montreal Games in 1976 but did not take home a medal.
Princess Anne, who will present the prizes later, was watching from the stands with a large royal contingent as the result went down to the wire.
Among the spectators were the Duke and Duchess of Cambridge, Prince Harry, the Duchess of Cornwall and Phillips' husband, the former England rugby player Mike Tindall.
Their silver takes Britain's medal tally to four after a silver in the women's cycling road race and bronze in both the men's team gymnastics and the women's 400m freestyle swimming.
There is also the chance of further medals later for Cook and King, who at 51 is the oldest female member of Team GB, when the individual eventing competition culminates later.
The top competitors all ride again in the show-jumping and their score for that round is added to their overall total to determine the rankings.
Phillips said the last three days had been an "emotional rollercoaster" but hailed the thousands who had turned out to support the British team.
"It's incredible, a massive lift when you come into the arena... I'm really grateful to everyone who has come and cheered for us. All week it has been the same," she said.
Holding the equestrian events in Greenwich near to the rest of the action, instead of in a location away from the capital, has been seen as a major success.
The medal has given British fans a cause for celebration after some disappointments in the early stages of the Games.
Mark Cavendish was hotly tipped to take gold in the men's cycling road race on Saturday but Briton were nowhere near the medals.
And Tom Daley and Pete Waterfield were strong medal hopes in the 10m platform diving but one poor dive cost them dearly and they finished fourth.
Mayor of London Boris Johnson joked on a visit to the beach volleyball in Horse Guards Parade on Tuesday that Britons, as the Olympic hosts, were holding back out of politeness.
"I think we are showing great natural restraint and politeness as host nation in not hoarding the medals more so far," he said.
With big hopes in many events yet to come including sailing, rowing and cycling, the British Olympic Association (BOA) insists Britain is still on course for a gold rush despite the mixed start.
BOA chef de mission Andy Hunt said: "There's no sense at all amongst the team that we are not delivering. The team remains confident and positive. We are about where we expected to be at this stage in the competition.
"It's really as we come in towards the end of the first week that we start to see our opportunities really ramp up in those traditional sports where we tend to excel."
BOA chairman Lord Moynihan has a personal interest in the final tally after accepting a bet from Australian Olympic chief John Coates back in 2005 for a magnum of champagne for every gold and a bottle for every silver or bronze that Britain finishes above or below Australia.
Britain are currently one gold behind their arch-rivals but Lord Moynihan said: "I've told John Coates that he hire a container because we're going to be in good shape by the end of these Games."
