As this battle was not part of the great works of Lars Rössle I translated the text from Mankell´s description of the battle. I had some problems with the images though...I do not understand why they are not as good resolution as the originals?
Battle of Walkiala April 29, 1790

The Swedish advance towards Walkiala continue through Selänpää to the bridge at Terasjoki which had been destroyed by the Russians. The bridge was repaired protected by two artillery batteries. Further on at Antilla village The Elfsborg Infantry battalion was deployed together with 2 guns. It was now 17.30 in the afternoon and reports came with news about enemy activity in Walkiala. The Russian Commander Major General Denisow had formed his troops in the wooded ridge northeast of Walkiala with his left flank anchored on the church and Ritala village, while the right flank was protected by a small frozen swamp (Vähälampi). In front of his position was open fields and the road turning south. The Russian line, well supplied with artillery, stretched from north to south about 1000 meter. The Swedish king Gustav III asked his soldiers if they preferred to rest during the night or to attack immediately. The response was that they were eager to do the latter and the Swedish forces were prepared to advance. The terrain forced the Swedes to advance in a narrow column on the road. The Kronoberg Regiment was in the van followed by the Västmanland and Östgöta Regiments. The Swedish 6 pounder artillery took a position at the Ottari farm and started to fire at the Russian line, around 1000 meters away. The two batallions of the Kronoberg Regiment deployed in the wooded terrain to the left of the road while suffering heavy fire from the Russian line. The Russian right flank now started to move against the Swedes. To counter this move the 2nd Östgöta Batallion together with the Jägers under Hjerta (Jämtland Jäger Batallion?) was detached and advanced towards the swamp on the Russian right flank. At the same time 7 Regimental guns were deployed in line with the infantry to the left of the road. On the extreme Swedish left the Västmanland 1st Batallion deployed. Major General Pauli commanded the Swedish left. On the Swedish right flank Major General Pollet brought up the 1st Östgöta Batallion beside the Kronoberg Regiment and the 2nd Västmanland Batallion. When the Swedish deployment was finalized under heavy Russian fire, the Russians started to withdraw their guns from the line. The Swedes then commanded “fix bayonets” and the whole Swedish line advanced and made a bayonet charge capturing the Russian position on the ridge, while the Russians retreated. It was now 22.00 and darkness prohibited any pursuit of the Russians. Total losses on both sides were 170 men and the Swedes captured the plentiful Russian supplies.
Swedish Forces under Gustav III (around 2500 men)
Kronoberg Regiment (2 Bat)
Västmanland Regiment (2 Bat)
Östgöta Regiment (2 Bat)
Hjertas (earlier Armfelts) Jäger Bat (1 Bat)
3lb and 6 lb Artillery
Russian forces under Major General Denisow
Plesanski(?) Regiment - 1800 men
Jägers - 900 men
Cossacks - 600 men
Bashkir - irregulars numbers unknown
Artillery - numbers unknown
Uniform jacket worn by Gustav III during the battle: