According to a description based on the work of Leszek Podhorecki, although the Poles were more aware that the battle was about to take place, the forces encountered one another in the darkness of the night, and Żółkiewski decided to organize his army rather than engaging immediately, which also gave the Tsardom of Russia time to prepare.
According to Mirosław Nagielski, however, the Poles under Żółkiewski purposefully chose to engage the opponent at that time, hoping to catch them asleep.

The Russian army was divided into foreign mercenary regiments on the right (north-west) flank, and the main Russian army on the center and left (south-east) flank.
The Russian battle line consisted of infantry (pikemen, musketeers, arquebusiers), mostly behind the village fences, with a second line of cavalry to the rear and on the left wing (where there were fewer fences).
The Russian artillery, left in the camp, played no role in the battle.
Polish units consisted primarily of cavalry, primarily the Polish hussars, with about 400 Cossack infantry on the left wing.
Another 200 infantry and two cannons would arrive later, and did not participate in the first part of the battle.

The battlefield, a flat agricultural field, was crossed by a high village picket fence, reinforced by improvised fieldworks, which allowed the Polish hussars to charge only through a narrow gap.

The battle began before dawn.
The first part of the battle consisted of Polish hussars repeatedly charging the fortified Russian positions, attempting to break them.
The Polish forces continued to make ferocious attacks, and Samuel Maskiewicz, a witness from one hussar company, claimed that his unit charged eight or ten times.
The Polish hussars' attacks on the infantry, hidden behind the fences, and using firearms, were not successful.

Hoping to take advantage of Polish exhaustion, Shuiski ordered a reiter unit to counterattack the hussars.

However, their attempt to employ caracole tactic ended disastrously when the Polish cavalry instead closed into melee after discharging their firearms.
As this Russian cavalry counterattack was mauled by the Poles, the left flank of the Russian army was broken and, in the ensuing confusion, Russian ranks broke and they were pushed back towards their camp gates.

While the center of the Russian army disintegrated, Russian regiments continued to hold on the right wing until they were overpowered, and the mercenary troops continued to put up strong resistance for several hours on the left wing.
Eventually when the Polish infantry and cannons arrived, the mercenaries were forced to abandon their positions.
A large portion of the foreign troops managed to retreat under the protection of their long infantry pikes in good order to the safety of their fortified camp (which was separate from the Russian camp).

The Polish forces now surrounded the two enemy camps.
Further, the mercenaries who took positions in the forest were surrounded as well.
However, the Russian fortified camp, filled with some still unbloodied troops (outnumbering the exhausted Polish force) was a serious obstacle.

Żółkiewski decided to attempt negotiations with the enemy, with significant success.
Abandoned by the Russians, the foreign mercenaries entered negotiations with the Polish troops and eventually surrendered, having reached satisfactory conditions.
The mercenaries were allowed to withdraw under the condition that they would not enlist with the Tsardom of Russia against the Polish–Lithuanian Commonwealth again.
Additionally, several hundred mercenaries chose to switch sides, enlisting with the Polish army.
According to a description based on the work of Leszek Podhorecki, although the Poles were more aware that the battle was about to take place, the forces encountered one another in the darkness of the night, and Żółkiewski decided to organize his army rather than engaging immediately, which also gave the Tsardom of Russia time to prepare. According to Mirosław Nagielski, however, the Poles under Żółkiewski purposefully chose to engage the opponent at that time, hoping to catch them asleep.
The Russian army was divided into foreign mercenary regiments on the right (north-west) flank, and the main Russian army on the center and left (south-east) flank. The Russian battle line consisted of infantry (pikemen, musketeers, arquebusiers), mostly behind the village fences, with a second line of cavalry to the rear and on the left wing (where there were fewer fences). The Russian artillery, left in the camp, played no role in the battle. Polish units consisted primarily of cavalry, primarily the Polish hussars, with about 400 Cossack infantry on the left wing. Another 200 infantry and two cannons would arrive later, and did not participate in the first part of the battle.
The battlefield, a flat agricultural field, was crossed by a high village picket fence, reinforced by improvised fieldworks, which allowed the Polish hussars to charge only through a narrow gap.
The battle began before dawn. The first part of the battle consisted of Polish hussars repeatedly charging the fortified Russian positions, attempting to break them. The Polish forces continued to make ferocious attacks, and Samuel Maskiewicz, a witness from one hussar company, claimed that his unit charged eight or ten times. The Polish hussars' attacks on the infantry, hidden behind the fences, and using firearms, were not successful.
Hoping to take advantage of Polish exhaustion, Shuiski ordered a reiter unit to counterattack the hussars. 
However, their attempt to employ caracole tactic ended disastrously when the Polish cavalry instead closed into melee after discharging their firearms. As this Russian cavalry counterattack was mauled by the Poles, the left flank of the Russian army was broken and, in the ensuing confusion, Russian ranks broke and they were pushed back towards their camp gates.
While the center of the Russian army disintegrated, Russian regiments continued to hold on the right wing until they were overpowered, and the mercenary troops continued to put up strong resistance for several hours on the left wing. Eventually when the Polish infantry and cannons arrived, the mercenaries were forced to abandon their positions. A large portion of the foreign troops managed to retreat under the protection of their long infantry pikes in good order to the safety of their fortified camp (which was separate from the Russian camp).
The Polish forces now surrounded the two enemy camps. Further, the mercenaries who took positions in the forest were surrounded as well. However, the Russian fortified camp, filled with some still unbloodied troops (outnumbering the exhausted Polish force) was a serious obstacle.
Żółkiewski decided to attempt negotiations with the enemy, with significant success. Abandoned by the Russians, the foreign mercenaries entered negotiations with the Polish troops and eventually surrendered, having reached satisfactory conditions. The mercenaries were allowed to withdraw under the condition that they would not enlist with the Tsardom of Russia against the Polish–Lithuanian Commonwealth again. Additionally, several hundred mercenaries chose to switch sides, enlisting with the Polish army.
Battle of Klushino