Favourites USA moved a step closer to a first women's volleyball Olympic gold with a 3-0 win against South Korea.
The Americans, who are ranked number one in the world, progressed to Saturday's final with a 25-20 25-22 25-22 victory at Earls Court.
They will meet defending champions Brazil, who beat Japan 3-0, in a repeat of the Beijing 2008 final.
Captain Fabiana Claudino scored 13 points as Brazil won 25-18 25-15 25-18 in Thursday's second semi-final.
USA have only dropped two sets in the tournament, with one of those coming against Korea in their 3-1 pool-stage win.
But the Asian team could not take the match past three sets again as USA's leading scorer Destinee Hooker bagged another 19 points to lead her team to victory.
USA coach Hugh McCutcheon said: "Our team battled and needed to battle to go to the final. I'm proud of the way our team played today."
Korea and Japan will meet in the bronze medal match on Saturday.