On his release, Marceau hurried to take part in the defence of Saumur against the Vendéean Royalists, distinguishing himself at the Battle of Saumur on 10 June 1793 by rescuing the representative Pierre Bourbotte from the hands of the insurgents. The National Convention voted him the thanks of the country and he received rapid promotion. His conduct at the Battle of Chantonnay on 5 September 1793 won him the provisional rank of general of brigade. On 17 October, he bore a great part in the victory at the Battle of Cholet, and on began his friendship with Jean Baptiste Kléber while on the field of battle.