After heavy fighting, the Royalists had succeeded only in pushing Essex's forces briefly back; they had given ground but not retreated from the battle, and his main force of infantry remained strong. In an attempt to proceed, Essex waved his infantry and light artillery forward. Rupert's cavalry was too weak to defend against this advance due to its large firepower, and he instead ordered two regiments of foot commanded by John Belasyse to halt Essex. The Parliamentarian records report they were "hotly charged by the enemies' horse and foot", who succeeded in forcing Essex slowly back, although the fight took four hours. In response, Essex called for Skippon to send him reinforcements; Skippon obliged by ordering a Mainwaring's Regiment of infantry to remove themselves from his line and march to replace some of Essex's exhausted soldiers. As soon as they arrived, they were charged by two bodies of cavalry and a regiment of infantry under John Byron, who forced the regiment to retreat; the Royalists hacked down the fleeing Parliamentarians and, according to Byron, his force "had not left a man of them unkilled, but that the hedges were so high the horse could not pursue them". Although the Royalists failed to press this attack due to the difficulty of manoeuvring cavalry in the field, and Essex briefly retook the ground, the loss of this infantry regiment opened a gap in the Parliamentarian line. If Rupert was able to drive through this gap, he would break Essex's army into two wings and be able to encircle them. Recognizing this possibility, he began redeploying the Royalist force: two regiments of cavalry and a regiment of infantry under his command would occupy Essex, while two regiments under Charles Gerard would push through the gap in the Parliamentarian line.