In the Scanian War, Ascheberg first was responsible for the defence of Bohuslän against attacks from Norway. His force won a battle close to Kviström. He left Bohuslän for Scania and acted as commander in a number of battles, often alongside king Charles XI. He distinguished himself at the Battle of Halmstad in August 1676, where he was wounded in the arm. After recovering in Gothenburg, he joined the army in Scania in time to play a significant part in the largest battle of the war, the Battle of Lund in December. He contributed actively to the Swedish victory in the Battle of Landskrona 1677 after which he was appointed Lieutenant Field Marshal. Before the war ended he received highest command of the Swedish army in Scania. In November 1678, after the hostilities had practically ended but before a peace treaty had been negotiated, Ascheberg was handed the highest position within the Swedish army; Field Marshal.