On 21 April, as Napoleon was winning the Battle of Landshut to the south, Deroy fought against Prince Franz Seraph of Rosenberg-Orsini's Austrian IV Armeekorps. He advanced on the right flank of Louis Davout's French III Corps and captured the village of Schierling. The Bavarians got no farther that day and Davout's attacks were also stopped. Bavarian losses were about 150 and French casualties 1,500, while the Austrians lost 3,000.