Paul Grenier's French corps crushed Franz Jellacic's Austrian division at Sankt Michael in Obersteiermark, Austria. Originally part of the Danube army of Archduke Charles, Jellacic's division was detached to the south before the Battle of Eckmühl and later ordered to join the army of Archduke John at Graz. As it retreated southeast toward Graz, Jellacic's division passed across the front of Eugène de Beauharnais' Army of Italy, which was advancing northeast in pursuit of Archduke John. When he learned of Jellacic's presence, Eugène sent Grenier with two divisions to intercept the Austrian column. Grenier's lead division duly intercepted Jellacic's force and attacked. Though the Austrians were able to hold off the French at first, they were unable to get away. The second French division's arrival secured a clear numerical superiority over Jellacic, who was critically short of cavalry and artillery. Grenier's subsequent French assault broke the Austrian lines and captured thousands of prisoners. When Jellacic joined John it was with only a fraction of his original force.