Christine Ohuruogu sank to her knees in disbelief tonight after becoming the first British woman ever to win the Olympic 400 metres title.
Ohuruogu produced a storming finish to overhaul favourite Sanya Richards and win in a time of 49.62 seconds and add Olympic gold to the world title won in Osaka last year.
The latest medal for Great Britain, with a total of 16 golds, makes it the most successful games for the country in terms of gold medals since 1908.
Richards tied up badly down the home straight and could only finish third behind Jamaica's Shericka Williams.
Just two years ago Ohuruogu was threatening to quit athletics after being suspended for a year for missing three out-of-competition drugs tests.
But she continued to train during her ban and returned to competition to win the World Championships in Japan last year ahead of team-mate Nicola Sanders, less than a month after the suspension expired.
Richards was absent from that race in Osaka after failing to come through the American trials, but looked the woman to beat in Beijing after cruising through the early rounds.
However, the 23-year-old went off too fast in the final and paid the price as Ohuruogu timed her run to perfection to secure Britain's second medal of the evening after Germaine Mason's surprise silver in the high jump.
Mason equalled his personal best with a clearance of 2.34 metres to finish second behind Russia's Andrey Silnov, who secured gold with a first-time clearance of 2.36m.
Russia's Yaroslav Rybakov took bronze after matching Mason's clearance of 2.34 but losing out on countback after two failures at 2.32m.
"I am a bit speechless but I am very happy and overwhelmed. Super-duper!" Mason said. "I did the best I could, equalled my PB and got a silver medal.
"I was a bit nervous but the crowd were amazing, they gave me energy and I did it. I most definitely exceeded expectations. My coach believed in me more than I believed in myself, which is good, you need a coach that is positive.
"I went way above my limits tonight - personal best and silver medal."
Mason, who was born in Jamaica but switched nationalities in 2006, had one failure at 2.29m and then opted to pass on that height, moving up to clear 2.32m and 2.34m with his first attempts.
That had the 25-year-old in gold medal position until Silnov also cleared 2.34m at the first attempt to maintain his flawless record in the competition, the Russian also clearing 2.36m in style.
Mason then failed with his three attempts at 2.36m but rightly celebrated Britain's first high jump medal since Steve Smith won bronze in Atlanta in 1996.
Team-mates Tom Parsons and Martyn Bernard finished eighth and ninth respectively after failing to clear better than 2.25m.
Ohuruogu admitted it was a dream come true to land Olympic gold.
She told BBC1: "I don't know where I am right now.
"You never think it's a reality, it's something you dream about. As I came across the line I thought 'oh my gosh' - I don't know what to say.
"I saw my brothers (as I crossed the line). It was so good to see them but I'm just so proud of myself.
"It's hard but my coach has always taught me that you have to go in expecting to win."