Battle of Porrasalmi Bay.

The Battle of Porrassalmi was a battle fought near the bight of Porrassalmi in Savonia on 13 June 1789, during the Russo-Swedish War in 1788 – 90.

The Swedish forces blocked the road to Mikkeli at a narrow watercrossing with a bridge near the bight of Porrassalmi. There they faced Russian infantrymen led by Ivan Ivanovich Michelson and Georg Magnus Sprengtporten.

Sprengtporten persuaded the Russians that Finnish troops were disloyal to the Swedish Crown and not going to fight, but his column was met with gunfire. Only infantry units participated in the fighting. The Russians were moving in a too-close formation and, despite numerous charges against the outnumbered Swedes, could not break through the defence and pulled back, covered by mounted Cossacks and Bashkirs.

The Russians lost 425 men killed and wounded, including their commander, General Georg Magnus Sprengtporten, who was seriously wounded, while the Swedes claimed to have killed and wounded 900. The Swedes lost in total 203 men dead or wounded.

Sprengtporten claimed that his defeat was due to a lack of cooperation between his officers and that the decision to leave the battlefield was unsound and taken without his consideration. He personally led a charge that succeeded in capturing a Swedish battery. Russian staff officer Ivan Sazonov, who also participated in the fighting, was said to have publicly praised the enemy's valour after the battle.