Marshal Bazaine had been ordered by Napoleon III to withdraw from Metz and concentrate at the fortress of Verdun but as he began the withdrawal, Prussian forces caught up.
The Prussian 2nd Army under Prince Frederick Charles was sent west to make contact with the French and when the 3rd Corps under von Alvensleben came under fire, they assumed it was a rearguard, but soon realised it was in fact the whole 2nd Army and threw in all available troops.
The surprise stalled the French, and with Bazaine more concerned about communications with Metz than Verdun, the advance halted. Later in the day the Prussian 10th Corps arrived on their left to shore up the defence and the French move on Verdun was abandoned.
Casualties on the Prussian side were heavy but they achieved their objective of delaying the French.

To the east of Mars-la-Tour up to the west bank of the Moselle, North-eastern France. (France)