Nathan Robertson and Gail Emms let slip five match points before beating Thailand's Sudket Prapakamol and Saralee Thoughthongkam on the sixth match point to set up an all-English mixed doubles final at the World Championships in Madrid.
They play two of their closest friends in the final after Anthony Clark and Donna Kellogg beat Koo Kien Keat and Wong Pei Tty of Malaysia.
Robertson, who had to pull out of last year's championships when he tore ligaments in practice on the eve of the event, said: "It's wonderful for English badminton. Anthony has been one of my closest friends for 12 years.
"I would not wish to play anyone else if I had been able to choose.
"We are sharing a room and we are so excited. We are going to do the same tonight as yesterday - go to the same restaurant and then watch a movie."
He added: "The match was amazing. There was no difference between the pairs out there. It was incredible."
Emms said: "It's great for English badminton. The training has been brilliant and we have really worked hard as a team."
Robertson added: "Anthony and Donna are now playing at the same level as us. We have been waiting for them to have a great championships and they have had it here."