In June 1941, she returned to Messina, where she was assigned to escort and patrol service in Sicily and the lower Tyrrhenian Sea; occasionally she was to be found patrolling between Tripoli and Bengasi. During one of her operations, she assisted in the recovery of seamen after their torpedo boat Esperia was sunk off Tripoli; later, in the January of 1942, she assisted the destroyer Maestrale. Following the Allied invasion of Sicily in September of 1943, she was moved first to Brindisi, then to Fiume. On 8 September 1943, the day Italy signed her armistice with the Allies, the vessel was located in Fiume undergoing equipment repair, together with the Stella Polare, the Spiga and the Pigafetta. Because she was unable to move under her own power, her crew sabotaged her to prevent her from falling in German hands, then abandoned her; their attempt to make the vessel unusable to the Germans was ultimately unsuccessful. The crews of the above vessels, together with one thousand soldiers, sailed from Fiume aboard the M/N Leopardi.

The Giuseppe Dezza was captured by the Germans and extensively repaired. On 9 June 1944, under the designation TA35 (Torpedoboot Ausland), she was placed on duty to serve the Kriegsmarine. The TA initials referred to requisitioned non-German torpedo boats. As the TA35, the Giuseppe Dezza performed escort operations along the Dalmatian coast in the company of two other former Italian torpedo boats, the TA21 (former Insidioso) and the TA22 (former Missori). Her service to the Kriegsmarine abruptly ended on 17August 1944 when she hit a mine and sank in the Channel of Fasana. The Channel of Fasana lies between Pola and Rovigno, in Croatia. Seventy-one crewmembers perished. There have been some questions concerning how the vessel was ultimately lost. One version holds that the TA35, after hitting the mine and sinking in Croatian waters, was recovered and brought to Trieste for repairs. She was then sunk during an aerial bombardment and demolished at the end of the war. Another version argues that the vessel sank in the channel of Fasana. This is confirmed by Kriegsmarine files, which are considered accurate through the end of 1944; these have the TA35 sinking at the precise co-ordinates in the Croatian channel where the vessel rests today.

The wreck of the TA35 was identified by divers, thanks to the discovery of the stern. Beneath a thick layer of biological encrustations, they found the name, “Dezza.” Today, the wreck lies on the sea floor at a depth of 35 meters. It is broken into two pieces, which lie separated by a distance of 200 meters. The bow section lies on its side, while the stern section lies upright. One of the very first things that divers see as they descend onto this historical wreck is the stern gun pointing towards the sky, as if on the lookout for an approaching enemy.