Celeste Mucci and Camryn Newton-Smith started the final day of the heptathlon in the long jump and javelin.
Mucci, who started the day in fourth, jumped to 6.13m and remained within sight of the podium before finding a personal best in the javelin, her weakest event, with a throw of 43.03m to put her into third.
Teammate Newton-Smith looked to improve from day two and started well with 5.66m jump then a personal best of 44.87m in the javelin as she moved up the table.
It came down to the final event, whether Mucci would hold onto a bronze medal but she needed to hold off Adriana Rodriguez and Adrianna Sulek.
Mucci tried to close the gap created and hold on to the bronze, but Rodriguez and Sulek were too strong as Mucci had to settle for fifth, which is the best finish by an Australian at the World U20s.
It might be raining here in Tampere, but our positive heptathlete girls found it ‘refreshing’! Celeste Mucci finishes fifth overall with 5865 points and Camryn Newton-Smith is fifteenth overall with a score of 5487 and a new PB! #Tampere2018 pic.twitter.com/TSedNlSvCc
— Athletics Australia (@AthsAust)