Lapisse became a Commander of the Légion d'Honneur on 14 June 1804. That year he was appointed to command a brigade in the 1st Division in Marshal Pierre Augereau's VII Corps at Brest. The 1st Division was present at the Capitulation of Dornbirn on 13 November 1805 when Franz Jellacic surrendered an Austrian division numbering three generals, 160 officers and 3,895 soldiers to Augereau. At the Battle of Jena on 14 October 1806, Lapisse led a brigade in Jacques Desjardin's 1st Division of VII Corps. The unit included four battalions of the 16th Light Infantry Regiment. On 24 December, Desjardin's division secured a bridgehead on the Wkra River at Kołoząb against strong Russian resistance. While this struggle was taking place, Lapisse took a task force downstream, surprised the bridge guard at Pruszkowo and gained an additional crossing. He fought at the Battle of Golymin and was promoted to general of division a few days later on 30 December 1806.