He won a smart victory over the III Prussian Corps in the Battle of Wavre , on 18 -- 19 June 1815 .
It was then too late , as by the time this battle was over , Napoleon had already lost at Waterloo .
He won a smart victory over the III Prussian Corps in the Battle of Wavre , on 18 -- 19 June 1815 , but it was then too late , as by the time this battle was over , Napoleon had already lost at Waterloo .