- Katherine Grainger wins first gold after claiming silver in previous three Olympics
- Eric Murray and Hamish Bond power to victory in men's pairs for New Zealand
- Fellow Kiwi Mahe Drysdale clinches gold in men's single sculls
- Germany ease to victory in men's quadruple sculls from Croatia and Australia
British rower Katherine Grainger ended her 12-year wait for Olympic glory after winning gold in the women's double sculls on Friday.
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 twice in quadruple sculls and once in the coxless pair, had targeted London 2012 as her final chance of success on the big stage.
"I am a bride at last," she told reporters. "I did seriously consider what I would do after Beijing. For anyone who was there, Beijing was a really tough result and I wanted to make sure I continued for the right reasons.
"As soon as I made the decision, there was never a doubt. I have had three fantastic years."
The British duo were huge favorites for the race and did not 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.
"Just before halfway I knew we had won it," said 29-year-old Watkins.
"With the crowd there was no way anything was going to go wrong. We had time to enjoy it, which is more than you can dream of."
Their success makes them just the third and fourth British women to win rowing gold at any Olympics, 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.
New Zealand's Beijing bronze medalist Mahe Drysdale triumphed in the men's single sculls after coming home ahead of the Czech Republic's 2008 runnerup Ondrej Synek and Great Britain's Alan Campbell.
Defending champion Olaf Tufte of Norway could only manage third in the "B" final.
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 German 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.
Poland, who won the 2008 gold, finished last.