The armies finally meet on the morning of July 25 at the village of Hastenbeck, southeast of Hameln, where Cumberland, believing his army ready for battle, has adopted a defensive position.

The commander of the French right flank, general François de Chevert, is ordered to engage Hanoverian troops at the village of Voremberg, but fails to drive them out.

As the French left flank under general Duc de Broglie is still crossing the Weser near Hameln, d'Estrées decides to postpone the battle until all his troops are drawn up.

The following day sees the Hanoverian army holding on a line from Hamelin to Voremberg.

Their right flank is anchored on the Hamel river and Hastenbach creek.

The center of the Hanoverian front is deployed north of the town of Hastenbeck, and an artillery battery is situated on high ground behind the town.

The Hanoverian left consists of two entrenched batteries, with grenadier battalions protecting the guns.

The left flank is anchored on the Obensburg.

Cumberland makes the mistake of assuming the hill to be impassable to formed troops and deploys a meager three Jäger companies on its summit, effectively leaving the Hanoverian left flank in the air.

General Chevert is ordered to flank the Hanoverian position with four brigades of troops from Picardy, la Marine, Navarre, and Eu.

This force advances at 9 AM toward the Obensburg in three battalion columns and quickly overwhelms the Jägers.

Cumberland, seeing his position threatened from the rear, orders his reserves and the grenadier battalions protecting the guns to recapture the Obensburg.

The use of these grenadier battalions in the counterattack on the Obensburg means that they are no longer available in the center when the main French attacks go in against the Hanoverian center.

The French main attack consists of general d'Armentieres's attack against Voremberg with five brigades of infantry plus four regiments of dismounted dragoons.

At the same time, the French center assaults the battery immediately north of it.

The Hanoverian grand battery is able to repulse several of the French attacks, but eventually the guns are overrun.

When the Hanoverian reserve infantry arrives on the Obensburg, they are able to turn the tide momentarily, but as Cumberland has begun to withdraw his army, they are unable to maintain the now-isolated position for long.

During the battle, Hastenbeck is almost completely destroyed, only the church, the manse, and the farm house remain intact.

The French have won a narrow victory over Cumberland here, but as he retreats his force begins to disintegrate as morale collapses.

The French ministers, deeply unhappy with d'Estrees due to the extremely slow advance of his army, have decided to replace him, despite his victory, with Armand de Vignerot du Plessis, Duc de Richelieu, who had recently distinguished himself leading the French forces that had captured Minorca.

Arriving shortly after the Battle of Hastenbeck with the Anglo-German Army of Observation retreating rapidly from him, the Duc leads his army in pursuit.

Richelieu's orders follow the original strategy of taking total control of Hanover, then turning west to offer assistance to the Austrians attacking Prussia.