New Zealand needed extra time to get past Fiji 22-17 and end their hopes of reprising their men’s gold while France outscored Britain four tries to three for a narrow 26-19 win in the second of the semis.
The two winners meet later on Saturday to decide the gold with Britain and Fiji to tussle for bronze.
New Zealand, who had not conceded a point in their last two matches, opened the scoring after five minutes when Gayle Broughton took advantage of an errant pass to dot down but the Fijian response was immediate with Vasiti Solikoviti scoring to see the islanders 7-5 ahead.
New Zealand should have regained the lead before halftime when Ruby Tui broke through middle but was chased down by Alowesi Nakoci, who knocked the ball out of her hands as Tui was looking to dive over for the try.
Fiji’s tackling set up their second try after the restart as Tui lost possession in a crunching hit to allow Fiji to gather possession and put Solikoviti over for her second try.
But New Zealand then regained the advantage with two tries that looked to wrap up the result. First, Portia Woodman extended her Olympic try tally to 15 with a break down the right wing and then Stacey Fluhler then put New Zealand ahead just before the final whistle.
Fiji, who edged Rio gold medalists Australia in a dramatic quarter-final, refused to concede and took the contest into extra time with a dramatic break and sprint to the corner from Reapi Ulunisau. Viniana Riwai could have won the game with the conversion but her effort was not good enough.
New Zealand gathered possession from the kick off in sudden-death extra time and took their time before Broughton powered over for a place in the finals.
France stormed into a 21-12 halftime lead over Britain as they scored three converted tries through Anne-Cecile Ciofani, whose parents were both Olympians, Seraphine Okemba and Coralie Bertrand, who scored from a clever kick from Jade Ulutule.
Jasmine Joyce used her incredible pace to score two tries for Britain and keep them in the contest.
Ciofani got a quick score after the break to extend the French lead but Hannah Smith brought Britain back to within seven points with two minutes left, only for the British to squander a late chance as they gave away a penalty in attacking for the equaliser.
The final will kick-off at 9pm New Zealand time.
