So the allied forces do what any other force would have done, they occupy the central position of the battlefield, aka "Pratzen Heights", and launch an attack on Napoleon's right formation. Things suddenly seemed great, the enemy right was crumbling while they were winning, something odd happened..
Scouts reported a sudden reinforcement from Vienna, wait, a sudden confusion erupted in the enemy camp, how is this possible? This was strange. But when it comes to the famous Marshal of Napoleon, i.e. the famous iron marshal, "Louis-Nicolas Davout", nothing is impossible. This lad just marched with his 10,000 troops, covering 70 miles in just 2 days!!
Lo and behold, suddenly the weakened right flank is restored to all-powerful now. Those fresh pairs of 10,000 boots change the situation. Now, due to this right flank push, the enemy reduced troops from the centre, i.e., the Pratzen Heights, in the hope of defeating the enemy from the right side, but the situation changed. Now it's time for a counterattack. Suddenly, Marshal Lannes took the enemy by surprise and launched an all-out attack on "Pratzen Heights". This sudden and powerful attack shook the enemy while the right flank started pushing the allied forces back.