Josefin Olsson advanced after a tough start to the regatta, where the Swede was initially in 26th place.
During Friday's penultimate race, number nine in the order, the sailor had a hard time and ended up in 22nd place.
Competitors such as Israel, the Netherlands and Australia took the lead in the water off the small island of Enoshima a few miles southwest of Tokyo where the Olympic sailing is decided.
Danskan Rindom leads
The result means that the Swede slips down from bronze place to place four in the summary.
Leading is still the Dane Anne-Marie Rindom, followed by the Netherlands' Marit Bouwmeester.
The last race before the final will be decided later on Friday.
A total of ten races are done in the basic round for laser radial and laser before the final competitions on Sunday.