When Carl Johan Adlercreutz continued his summer offensive, he saw an excellent opportunity to encircle the Russian main army at the town of Nykarleby.

On the way to Vaasa they encountered a smaller Swedish unit led by Major Carl von Otter and a small battle ensued.

The Swedes decided to stop in Nykarleby to celebrate Midsummer while the Russian troops were retreating.

Legend says that Georg Carl von Döbeln, who was marching in front of the Pori Regiment, became so angry when he saw the Russians retreat after having burned the bridge, and that the surprise attack had failed, that he ran out in the river, loyally followed by his regiment.

The Swedes won a small victory at Nykarleby, but the ensuing festivities delayed the march to the south in such a manner that they could not support the Swedish landing force in Vaasa.