Katherine Grainger ended her 12-year wait for Olympic glory after winning gold in the women's double sculls.
The 36-year-old Scot, partnered by Anna Watkins, punched the air in delight after exorcising the demons of Sydney, Athens and Beijing.
Grainger, who had suffered the agony of being made to settle for silver in those three previous games, had targeted London 2012 as her final chance of success on the big stage.
The British pair were huge favorites for the race and did notn't disappoint, powering their way to an incredible 23rd consecutive victory.
Watkins, who won a bronze in Beijing in 2008, teamed up with Grainger just two years ago.
Since then, the British team have been unbeatable, winning two World Championship titles as well as all three World Cups in 2012.
Grainger and Watkins' success makes them just the third and fourth British women to win rowing gold, following Thursday's triumph by Helen Glover and Heather Stanning in the women's pair.
Kim Crowe and Brooke Pratley took silver for Australia with Poland's Magdalena Fularczyk and Julia Michalska grabbing bronze.
Meanwhile, New Zealand enjoyed a glorious day on the water at Eton Dorney after claiming gold in both the men's pair and single sculls.
New Zealand duo Eric Murray and Hamish Bond maintained their three-year unbeaten record after tearing through the field.
France's Germain Chardin and Dorian Mortelette claimed silver with British duo George Nash and Will Satch taking bronze.
Mahe Drysdale triumphed in the men's single sculls after coming home ahead of the Czech Republic's Ondrej Synek and Great Britain's Alan Campbell.
In the men's quadruple sculls final, world champions Australia were forced to settle for bronze with Germany taking the Olympic title ahead of Croatia.
The crew of Karl Schulze, Lauritz Schoof, Phillipp Wende and Tim Grohmann led from start to finish to win in a time of 5 minutes, 42.48 seconds.