The breakthrough on the British Eighth Army's front was to be made through the Argenta Gap, crossing the Rivers Senio and Santerno towards the Po at Ferrara and releasing armour to swing left and race across country to meet the advancing U.S. Fifth Army completing the encirclement of the German divisions defending Bologna.

The Commandos were to clear the spit, securing the flank of the Eighth Army, and thus foster the idea the main offensive would be along the coast and not though the Argenta Gap.

40 Commando (RM) conducted a feint attack to the south, crossing the River Reno and clearing and holding its north bank.

40 (RM) was supported by the 28th Garibaldi Brigade (Partisans), Royal Artillery, and the armour of the North Irish Horse.

No.2 was to land above the Bellocchio Canal and thereafter head south and capture the two bridges across it and prevent German reinforcements crossing.

The lagoon crossing (marked in advance though not too successfully by Combined Operations Pilotage Party 2 and M Squadron, Special Boat Service), took far longer than planned due to the exceptionally low water level and exceptionally muddy lagoon bottom, which was as deep as chest high.

The Commandos struggled through the muddy waste all night, manhandling their boats, and eventually reached the Spit at first light, over 4 hours behind schedule.

The following day, 3 April, Royal Engineers made serviceable the blown bridge and the Commandos moved over the canal, supported by tanks of the North Irish Horse.

The north bank of the Valetta was found to be very heavily defended, requiring a full-scale attack, which was later conducted by the 24th Guards Brigade.

Hunter single-handedly cleared a farmstead housing three German MG 42s, after charging across 200 metres of open ground firing his Bren gun from the hip.

Anders Lassen, a Danish soldier of the SBS, was also awarded a posthumous Victoria Cross for his actions during Operation Roast on 8 April 1945 at Lake Comacchio.

The 2nd Commando Brigade had succeeded in taking and clearing the entire spit, securing the eastern flank of Eighth Army.

Lieutenant-General Sir Richard McCreery, commanding the British Eighth Army, sent a message to Brigadier Tod proclaiming "you have captured or destroyed the whole enemy garrison south of Port Garibaldi."