Louisa Reeve and Olivia Whitlam finished second in the women's pair repechage to become the fourth British rowing crew to qualify for a final.
The British duo finished behind winners Juliette Haigh and Nicola Coles of New Zealand in the four-boat race.
Team GB's other rowing finalists are the men's eight, the women's quad and women's double sculls.
In the women's lightweight double sculls, Hester Goodsell and Helen Casey won their repechage to reach the semis.
Reeve and Whitlam are in contention for a rowing medal
Goodsell and Casey needed to finish in the top three to seal a place in the semi-finals or face relegation to the C race and they qualified in style, comfortably beating the Greek and Cuban crews.
"I'm really pleased with what we've achieved so far," said David Tanner, Team GB’s rowing team leader.
"We've shown the strength in depth again which began to emerge at the World Championships in Munich.
"Here in Beijing those who have needed to lift their standards have done so. Now we will see some fantastic racing in the next few days."
Elsewhere, the United States and Australia qualified for the men's eight final.
The defending champions edged the Australians, who had three-times Olympic champion James Tomkins on board, in a thrilling race on Lake Shunyi.
Australia were in charge coming into the final stretch but then the US, who led for the first 1,000m, responded to hold on for the line.
The two teams will face Britain and World Champions Canada in the blue riband event on Sunday along with the Netherlands and Poland, who narrowly beat host nation China.
Crew member Micah Boyd said the US were grateful for a second chance after they lost their heat to Britain.
"On Monday we raced way too high like 37, 38 (strokes per minute) and some of the guys in our stern are, like, 6ft 8in, 6ft 9in. So we went to 36, 37 and that helped us a lot and made us more efficient," said Boyd.
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