The Lajos Kossuth government decided to withdraw the Hungarian troops from Komárom to southern Hungary without consulting Görgei, the war minister, the only one authorised to make a military decision.

The Hungarian counter-attack, supported from the southern Herkály grange by VII Corps cavalry led by General Ernő Poeltenberg, threatened Schlick's left flank with separation from the rest of the imperial army.

The imperial army was saved by the Russian division (led by Lieutenant General Fyodor Panyutyin) and the Austrian I Corps Simbschen-Brigade; Poeltenberg retreated to escape encirclement, stopping the Hungarian advance.

Hungarian III Corps General György Klapka ordered several counter-attacks to reoccupy the strategic position but, despite initial success, his troops were forced to retreat.

Haynau was unaware of the battlefield situation and, believing his troops were victorious, ordered his center (IV Corps) to withdraw; this put his army in danger from a Hungarian attack.

[4] Colonel József Bayer, Görgei's Hungarian Operational Office chief, and government commissioner János Ludvigh wrote to Lajos Kossuth in Pest about the lost battle.

He blamed his subordinates for defeats around the Vág, their inaccurate reconnaissance, and the intervention of Russian troops at Győr and in the Battle of Pered, and believed that he could impose his will on the Austrians with a decisive attack against Haynau's army.

One, with troops from Bácska and Bánság, the Transylvanian Army (led by General Józef Bem) and Colonel Kazinczy Lajos' division, mobilized in eastern Hungary to defend the Tisza River; its headquarters was in Nagyvárad.

[20] After meeting with the delegation from Budapest and a discussion with József Bayer, Görgei said that the Council of Ministers plan was wrong; the region had no food resources due to months of fighting, and the two south Hungarian strongholds (Temesvár and Arad) were in Austrian hands.

[23] On 28 May, Komárom commander György Klapka ordered the construction of Sandberg (Sand Mountain): a fortress with casemates at Monostor to defend the fortified encampment from attacks from the west and to control the road from Ács and Danube traffic.

These were a total of 352 infantry companies and 70 cavalry squadrons (64,743 men), 12,454 horses and 276 cannons, commanded by Field Marshal Lieutenant Julius Jacob von Haynau.

[30] Morale was high before the battle, due to Haynau's victories and the presence of young Franz Joseph I and the Archdukes Ferdinand Maximilian and Karl Ludwig in the camp.

[33] Although Hungarian morale was lower than that of the Austrians because of previous defeats, the troops still believed that Görgei's military genius would prevail; despite what they considered minor setbacks, and with a counterattack similar to the Spring Campaign, victory could still be achieved.

[33] The Hungarian troops (quartered in the barracks or the trenches) were more rested than the mobile imperial army, but many – especially in VIII Corps, designated to defend the fortress – had no close-combat experience.

He wanted a decisive victory against the Hungarians, forcing them to capitulate, to demonstrate, that he won the war without Russian help, and to restore the damaged honor of the Habsburg Empire, seen as incapable of dealing alone with a revolution.

Under General János Damjanich, who broke his leg on 27 April, it was one of the most renowned corps of the Hungarian army; the third and ninth divisions of the 19th (Schwarzenberg) infantry regiment were especially courageous.

The Ludwig cavalry brigade was ordered to occupy the southern portion of the Ács forest and maintain contact with Wohlgemuth's reserve corps from the Herkály grange.

He did not expect a battle that day; the previous night, foreseeing that Kossuth would remove him from leadership of the army, he dictated a memorandum to officer Kálmán Rochlitz explaining his actions.

[32] When the corps approached Herkály, brigade leader General Lajos Benedek sent an infantry company and a half-company of chevau-légers to form a skirmish line; attacked by the hussars, they were forced to retreat.

To support these actions from the center, many Hungarian infantry units from the Ács woods were ordered to rush in that direction,[71] and this helped the Austrians, now in numerical superiority, to carry out a successful counterattack.

The Schönhals division, the Sartori brigade, the Baden battalion, supported by a rocket battery forced the weakened Hungarians to retreat to the Eastern section of the Ács woods, then in the Cherry Forest (Meggyfa-erdő).

After surveying the battlefield from a platform, he wrote a note to the troops questioning their resolve, and asking: is there no Hungarian left, who is ready to die for his homeland?, before galloping off to organize the cavalry attack which will constitute the most emblematic part of the battle: the great hussar charge.

[82] When a Hungarian rocket exploded over the first-aid station, Haynau quickly moved his headquarters back to Bana, while the emperor was convinced only with difficulty by his concerned entourage to leave the village.

Not long after that the 3000 hussars, led by General Poeltenberg, started their attack against the imperial center, but their left wing was immediately hit by the enemy artillery, which caused them to fall behind, so the whole line turned leftwards.

[82] Görgei, who thanks to his big (190 cm to the shoulder), powerful horse, named Csóka (Jackdaw),[83] rode way ahead of his hussars, observed that on the right side an enemy line formed of Polish uhlans threatened the Hungarian cavaleries flank.

So he tried to give a signal to General Poeltenberg to reorganize the lines, turn them towards the uhlans, and attack, by taking off his feathered hat and waving it, which caught the attention of the enemy.

[85] The most probable theory, accepted by the important researchers of the Hungarian 1848-1849 Revolution and Freedom War (for example Róbert Hermann,[87] Tamás Csikány,[85] Zoltán Babucs)[83] is that he was hit by a splinter of an enemy projectile which exploded over his head.

[90] The hussars continued the attack, but the fire of the Russian artillery, and the counterattack of the (imperial) uhlans and the (Archduke John) Dragoon regiment, from the front and flanks halted them, and after a harsh melee, they forced them to retreat.

[40] Lajos Benedek, the Austrian general of Hungarian origin in a letters to his wife, characterizes the situation in which he was in that moment, and his opinion about Haynau's order, with bitter and harsh words: The dead lay round me as if in a shambles.

After all the Austrian units left the town, they retreated towards their military encampment from Mocsa, where they arrived around 10,30 p.m.[40] At the end of the battle the Hungarian troops occupied Ószőny as the result of Görgei's clever plan to lead a daring cavalry attack in the Herkály form, which forced the Austrian commanders to transfer many of their units, which defended Ószőny, to the center of the battlefield, making possible for Klapka to take back this important strategical point.