The spring of 1813 found Grenier serving under Eugène in Saxony as Napoleon assembled a new army to replace the one destroyed in Russia. In the Battle of Möckern on 5 April, Grenier was wounded. After the summer armistice, Eugène and Grenier returned to Italy to prepare the Italian army for hostilities with Austria. One authority notes that Grenier was "perhaps the best commander in Italy" at this time and was assigned to lead the 1st Corps. During August 1813, he led his troops with success against the Austrian army of Johann von Hiller near Villach. When Hiller established a bridgehead across the Drava River at Feistritz an der Drau, Grenier attacked and defeated the Austrians on 6 September. The Franco-Italian strategic situation soon deteriorated and Eugène slowly withdrew to the Adige River in October and November. On 31 October, Grenier won a smart victory over Christoph Ludwig von Eckhardt's column at Bassano del Grappa, sending the Austrians fleeing into the mountains. He commanded his corps under Eugène at the Battle of the Mincio River on 8 February 1814. In independent command, he defeated an Austrian force at Parma in northeast Italy on 2 March 1814. Hostilities ended in mid-April when the news of Napoleon's abdication arrived.