On the track, 100m hurdlers Lotta Harala and Saara Keskitalo were the only Finnish athletes to advance from the heats, but the former was then disqualified for a false start in her Semi-final, while Keskitalo came eighth in hers.
A national record in the women's 3000m steeplechase heats wasn't enough for Ilona Mononen to advance, while other than Kosonen, Finland have had no success in the field events either.
Tomorrow, the Nordic nation's hopes of getting onto the medal table will turn to Saga Vanninen, who begins two days of competition in the heptathlon.
Still only 22, Vanninen was a two-time world U20 champion and in 2023 added a gold medal in the European U23 championships on home soil.
This year, she has shot to fame with pentathlon gold in both the World and European Indoor Championships, before taking her second European U23 crown over seven events in Bergen, Norway two months ago, setting a new national record in the process.
Ninth in the world championships in Budapest two years ago, Vanninen is now hoping to upset the more established names in the event, such as Katarina Johnson-Thompson of Great Britain, Anna Hall of the United States and Belgium's Nafi Thiam.
Her coach, Estonian decathlon legend Erki Nool, believes Vanninen is in the right shape and can go even better than at the European U23 event.
"Saga looks sharper than in Bergen. She is in better physical condition. By all accounts, she should do better than in Bergen," Nool told Helsingin Sanomat.
While the Tampere woman knows the competition will be tough, she alludes that she is in with a chance of getting Finland's first medal of the championships.
"The medals are pretty tight at these games. The competition is really tough, and I'm in the group of contenders," she said.
In tomorrow's evening session, Vanninen and her competitors take on the 100m hurdles, high jump, shot put and 200m sprint. The event concludes on Saturday with the long jump, javelin and 800m.