Charlotte Dujardin made a record-breaking Olympic debut that put Britain top of the team dressage standings.
The 26-year-old smashed the Olympic record of German Kristina Sprehe's that had stood for just two hours, scoring 83.66% on Valegro.
It was only 0.42% off matching Edward Gal and his horse Totilas' world record set at the 2009 European Championships in Windsor.
And a capacity 23,000 audience in Greenwich Park's roared its approval as Dujardin set the competition alight.
Barely 20 months ago, the Enfield-born rider had never performed a grand prix test, but now she is the Olympic record holder and also holds the grand prix special world record, set in Germany last April..
"It is an amazing opportunity to ride here, and I really wanted to enjoy it," she said.
"I would hated to have gone in there, put too much pressure on myself and made mistakes.
"I just wanted to go in and do what I do normally and have fun. Having the crowd behind me like that was amazing.
"I was hoping for an 80%, so to come to the Olympics and smash that is a little bit crazy, but I had such fun.
"It was such a buzz, I can't tell you. I just wanted to get in there and do my piece."