Great Britain completed a clean sweep of Olympic rowing finalists, with all 13 boats they entered into the regatta qualifying for medal races.
The only event Britain are not contesting at Eton Dorney is the women's single scull.
Britain, who have already won a gold and a bronze, ensured home interest in every other final at the Olympic regatta with semi-final victories from the men's four, the lightweight women's double scull and the lightweight men's double.
The British men's four laid down a marker ahead of Saturday's final with a thrilling victory over arch gold medal rivals Australia.
Andrew Triggs Hodge, Pete Reed, Tom James and Alex Gregory hit back from a length down to row through the Australians with a massive push in the last 500 metres.
Britain are looking to extend their golden dynasty in the men's four to 16 years following Olympic triumphs in Sydney, Athens and Beijing.
Australia claimed after winning the Munich World Cup regatta in June that their tactic of leading from the front had "scared the hell" out of Britain.
Thursday's performance will have gone a long way to de-bunk that claim - and it set up another sensational showdown for gold on Saturday.
Sophie Hosking and Kat Copeland finished strongly to beat key rivals Greece to win their double scull semi-final by a length.
And reigning lightweight men's double champions Mark Hunter and Zac Purchase, who are back on form at just the right time, completed a remarkable 100% return for Britain with a semi-final victory over key rivals France by half a length.