Having failed in its first offensive action at Montcornet, the 4th DCR regrouped and received more of its still-missing elements. De Gaulle hoped to strike the exposed southern flank of Guderian's advancing German XIX Corps with a large-scale attack that would cut enemy communication and supply lines by seizing the bridges over the Serre. But DeGaulle's hastily assembled 4th DCR would have to attack without infantry, without aviation and without antiaircraft defenses.

DeGaulle's division sent a powerful armored force into the opening, but unfortunately the tanks brought along almost no one else and came forward in piecemeal fashion. At first only the R35 light tanks of 2nd and 24th BCC advanced toward Crecy, they quickly retreated before a wall of German fire. On the German side, 10th Panzer Division had prepared a stout defense of the Serre bridges with numerous anti-tank guns, anti-aircraft guns and artillery; German engineers had mined all access roads. After the failure of the light tanks, the Bl-bis of the 46th BCC attacked the village of Chalandry, east of Crecy, in front of the Serre and some of them crossed the river at Mortiers. At 1100 the R35's resumed the assault on Crecy with the support ofD2 tanks. A violent fight raged for control of the bridge at Crecy, where the French lost several tanks but failed to take the bridge. Without infantry to secure the tanks against enemy infantry ambushes or clear out German anti-tank guns, the French armor failed to take the bridges on its own and De Gaulle had to withdraw his division.