Mixed doubles pair Nathan Robertson and Gail Emms will win at least a silver medal after becoming the first Britons to reach an Olympic badminton final.
The fourth seeds beat seventh seeds Rikke Olsen and Jonas Rasmussen from Denmark 15-6 15-12 in the semi-finals.
After running away with the first set, the Britons edged a tense second to earn their chance of going for gold.
They now face second seeds Jun Zhang and Ling Gao of China, who beat Danes Jens Eriksen and Mette Schjoldager.
The Britons were delighted with their win but were determined to keep their focus ahead of Thursday's final.
"In a way I feel great but on the other hand we still have a job to do
tomorrow and we have to focus on that," said Emms.
"We know what we have to do against whichever pair gets through and so now we
just have to try and stay as relaxed as possible and go out and do our best in
"I didn't really suffer from nerves and was very happy with the performance," said Robertson.
"We said during the match that we had to concentrate on taking control of the
game and we kept that focus."
In the semi-final, the Britons went straight onto the attack and took the first game comfortably.
But Robertson failed to put away an easy winner at the start of the second and the Danes seized their opportunity to build a 5-1 lead.
However, Robertson and Emms regained their composure and fought back to edge to a 10-9 lead.
They then held their nerve to secure the game 15-12 and earn their place in Thursday's final.
There they will play the Chinese second seeds, who beat Eriksen and Schjoldager 15-9 15-5.
There was an upset in the semi-finals of the women's singles when Mia
Audina Tjiptawan of the Netherlands beat top seed Gong
Ruina of China 11-4 11-2.
In the other semi, World champion Zhang Ning of China
defeated compatriot Zhou Mi 11-6 11-4.
In the men's singles quarter-finals, Korean Shon Seung-Mo beat Chinese second seed Chen Hong 10-15 15-4 15-10.
The result means the seventh seed Shon is the highest-ranked player left in the draw.
There were no such shocks in the women's doubles where the top four seeded pairs made it through to the semi-finals.